978-1-936114-59-7 - Real Science-4-Kids · chemistry. Chemistry is the study of matter which is a general term for what forms all living and nonliving things. Chemistry is concerned

Cover design: David KellerOpening page: David KellerIllustrations: Rebecca W. Keller, PhD

Copyright ©2013 Gravitas Publications, Inc.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. No part of this book may be used or reproduced in any manner whatsoever without written permission. Focus On Middle School Chemistry Student Textbook (softcover)ISBN 978-1-936114-59-7

Published by Gravitas Publications, Inc.www.gravitaspublications.com

IllustrationsChapter 9, 9.1: Art Today Chapter 10: All molecular coordinates were provided by the Brookhaven Protein Data Bank.Front cover: Water molecule showing both the bonding of two hydrogens to one oxygen and the van der

Waals radii of the atoms Back cover, inside title page: L-alanine molecule—one of the amino acids

Special thanks to Susan Searles for copyediting and review of the manuscript. Also, I’d like to thank the Keller kids (Kimberly, Chris, and Katy), the Chesebrough kids (Sam and Ben), and the Megill kids (Lorien, Lee, Joshua, and Joseph) for critical evaluation of the text. Finally, I’d like to thank Lina and Lillian McEwan for valuable input.

ContentsCHAPTER 1: MATTER 1 1.1 Introduction 2 1.2 Atoms 2 1.3 Periodic Table 4 1.4 Summary 7

CHAPTER 2: MOLECULES 8 2.1 From Atoms to Molecules 9 2.2 Forming Bonds 9 2.3 Types of Bonds 10 2.4 Shared Electron Bonds 10 2.5 Unshared Electron Bonds 11 2.6 Bonding Rules 11 2.7 Shapes of Molecules 12 2.8 Summary 13

CHAPTER 3: CHEMICAL REACTIONS 14 3.1 Introduction 15 3.2 Combination Reaction 15 3.3 Decomposition Reaction 16 3.4 Displacement Reaction 16 3.5 Exchange Reaction 17 3.6 Spontaneous or Not? 17 3.7 Evidences of Chemical Reactions 18 3.8 Summary 19

CHAPTER 4: ACIDS, BASES, AND pH 20 4.1 Introduction 21 4.2 The pH Scale 21 4.3 Properties of Acids and Bases 22 4.4 Measuring pH 23 4.5 Summary 24

CHAPTER 5: ACID-BASE NEUTRALIZATION 25 5.1 Introduction 26 5.2 Concentration 27 5.3 Titration 28 5.4 Plotting Data 29 5.5 Plot of an Acid-Base Titration 30 5.6 Summary 31

CHAPTER 6: MIXTURES 32

6.1 Introduction 33 6.2 Types of Mixtures 34 6.3 Like Dissolves Like 35 6.4 Soap 38 6.5 Summary 39

CHAPTER 7: SEPARATING MIXTURES 40 7.1 Introduction 41 7.2 Filtration 41 7.3 Evaporation 41 7.4 Solids, Liquids, and Gases 42 7.5 Chromatography 43 7.6 Summary 44

CHAPTER 8: ENERGY MOLECULES 45 8.1 Introduction 46 8.2 Nutrients 46 8.3 Carbohydrates 47 8.4 Starches 48 8.5 Cellulose 49 8.6 Summary 50

CHAPTER 9: POLYMERS 51 9.1 Introduction 52 9.2 Polymer Uses 52 9.3 Structure of Polymers 53 9.4 Modifying Polymers 54 9.5 Summary 55

CHAPTER 10: BIOLOGICAL POLYMERS: Proteins and DNA 56

10.1 Introduction 57 10.2 Proteins 57 10.3 Proteins Are Amino Acid Polymers 58 10.4 Proteins Form Special Shapes 58 10.5 Protein Machines 60 10.6 DNA 62 10.7 DNA Structure 63 10.8 Protein Machines on DNA 64 10.9 Summary 64

Glossary–Index 65

2 FOCUS ON MIDDLE SCHOOL CHEMISTRY

1.1 Introduction

What is chemistry? Have you ever wondered what the world and the objects in the world are made of? What is water exactly? Why do ice cubes float?

What are our hair and skin made of? Why is a marble hard but a jellyfish soft?

All of these questions, and others like them, begin the inquiry into that branch of science called chemistry.

Chemistry is the study of matter which is a general term for what forms all living and nonliving things.

Chemistry is concerned mainly with the properties of matter. All of the items we encounter on a daily basis are made of matter.

Balloons are made of matter.

Pancakes are made of matter.

Baseballs are made of matter. Even our bodies are made of matter. But what makes up matter?

1.2 Atoms

The fundamental building blocks of matter are atoms (a’-tǝms). The word atom comes from the Greek word atomos, which means “uncuttable.” During the 5th century B.C. (B.C.E.), the Greek philosophers proposed the idea that there must be some smallest uncuttable units of matter. They called these units atoms.

CHAPTER 1: MATTER 3

Today we know that atoms are composed of even smaller particles called protons (prō’-tänz), neutrons (nü’-tränz ), and electrons (i-lek’-tränz).

Protons and neutrons are roughly equal in size, but electrons are very much smaller than both protons and neutrons. Protons, neutrons, and

electrons are all much smaller than an atom.

Protons and neutrons combine to form the central core or nucleus (nü’-klē-ǝs) of an atom. The electrons

occupy the space surrounding the nucleus. This space is sometimes called the electron cloud.

The number of electrons in an atom always equals the number of protons. Notice that in the helium (hē’-lē-um) atom there are two protons and two electrons. Sometimes the

number of protons also equals the number of neutrons, as

with helium, but this is not always true.

Most of the space of an atom is actually

filled up by the electron cloud. The central core of an atom takes up

only a very small part of the total space.

On the other hand, almost all of the mass of the atom is in the protons and neutrons in the nucleus. The electrons weigh almost nothing compared to the nucleus, yet they take up all the space!


1.3 Periodic Table All of the atoms that make up the world are known. They are called chemical elements or just elements (e’-lǝ-mǝnts). Early in the 19th century, a total of 55 chemical elements were known, and many more were being discovered. Their properties were very different from each other, and it was difficult to organize them. In 1867, Dmitri Mendeleev (dmē’-trē men-dǝ-lā’-ǝf) organized the elements into what is now called the periodic table of elements.

In today’s periodic table, the elements are arranged horizontally from left to right in order of increasing atomic number. The atomic number is the number of protons in the nucleus of each atom. For example, carbon has an atomic number of 6, which means it has 6 protons in its nucleus. Oxygen (äk’-si-jǝn) has an atomic number of 8, which means it has 8 protons in its nucleus.

All of the elements have a symbol. For example, hydrogen (hī’-drǝ-jǝn) has the symbol “H,” and carbon has the symbol “C.” Notice that for these elements the symbol is the same as the first letter of the name. This is true for many elements because they have English names, like oxygen which has the symbol “O.” But some names come from other languages. The name for sodium (sō’-dē-ǝm) comes from the Latin word natrium, so it has the symbol “Na.” Tungsten comes from the German word wolfram, so it has the symbol “W.” Other examples include gold, which has the symbol “Au” from the Latin word aurum, and lead (led), which has the symbol “Pb” from the Latin word plumbum.

CHAPTER 1: MATTER 5

As we just saw, the atomic number tells how many protons the atom contains. In an atom, the number of protons equals the number of electrons, so this number is also the number of electrons in an atom. For example, the smallest element is hydrogen. It has an atomic number of 1, which means it has only one proton. It also has only one electron, since the number of protons equals the number of electrons.

Though atoms are very small, each one has a weight called the atomic weight. For most atoms the atomic weight is very close to the sum of the protons and neutrons in the nucleus. Both protons and neutrons have an atomic weight of 1. Electrons are so small that they are given almost no weight at all. The number of neutrons for an atom can be calculated by subtracting the number of protons from the atomic weight.

For example, the atomic weight of hydrogen is 1.0079, which is the number found below the name. To find the number of

neutrons, the number of protons (1) is subtracted from the atomic weight (1.0079 or 1); 1 - 1 = 0. This means that hydrogen has no neutrons and only one proton in its nucleus.

The largest naturally occurring element is uranium (yü-rā’-nē-ǝm).

It has an atomic number of 92, which means it has 92 protons and 92 electrons.

It has an atomic weight of 238.0289. To calculate the number of neutrons, the number of protons is subtracted from the atomic weight (238 - 92 = 146), so uranium has 146 neutrons.


The elements in the periodic table are arranged vertically according to their chemical properties. All of the elements in a single column undergo similar chemical reactions and have similar chemical properties. All of the elements in the far right-hand column are called the noble gases. They are similar to each other because they don’t react with other atoms or molecules. The elements in the far left-hand column are called the alkali (al’-kǝ-lī) metals. They are similar to each other because they react with lots of different atoms or molecules.

The periodic table of elements organizes a lot of information about the elements and their chemical properties. This table helps chemists predict the behavior of the elements and how they might interact with each other. Before all of the naturally occurring elements were known, Mendeleev used the organization of his table to predict many of the properties of the missing elements. The success of his predictions and the organization of his chart led to its acceptance as a major scientific accomplishment.

CHAPTER 1: MATTER 7

1.4 Summary

Here are the most important points to remember from this chapter:

• All things, both living and nonliving, are made of atoms.

• Atoms are made of protons, neutrons, and electrons.

• In an atom, the number of protons equals the number of electrons.

• All atoms (elements) are found in the periodic table of elements.

• The elements are arranged in the periodic table in groups that are similar.

CHAPTER 3: CHEMICAL REACTIONS 15

3.1 Introduction

What happens inside a battery? How does a car use gasoline to run? What happens to an egg when it’s fried in a pan? All of these situations are

examples of chemical reactions at work. Chemical reactions happen almost everywhere we look. They provide the energy that powers many things including cars, toys, plants, and animals. Our own bodies work by means of many complex chemical reactions.

A chemical reaction occurs whenever bonds between atoms and molecules are created or destroyed. The following are four general types of chemical reactions:

1. Combination (käm-bǝ-nā’-shǝn) reactions occur when two or more molecules combine with each other to make a new molecule.

2. Decomposition (dē-käm-pǝ-zi’-shǝn) reactions occur when a molecule decomposes, or breaks apart, into two or more molecules.

3. Displacement (dis-plās’-mǝnt) reactions occur when one atom kicks another atom out of a molecule.

4. Exchange (eks-chānj’) reactions occur when one atom trades places with another atom.

3.2 Combination Reaction

In a combination reaction, two or more molecules combine to form a single product.

The reaction of sodium and chlorine (klôr’-ēn) to make sodium chloride, or table salt, is an example of a combination reaction. In this reaction two sodium atoms combine with one molecule of chlorine gas to make two molecules of sodium chloride.


3.3 Decomposition Reaction

In a decomposition reaction, molecules of one type break apart or decompose to make two or more products. The breakup of water into hydrogen and oxygen gases is an example of a decomposition reaction.

3.4 Displacement Reaction

A third general type of chemical reaction is the displacement reaction.

In this reaction, one atom will remove another atom from a compound to form a new product.

The formation of sodium hydroxide from two water molecules and two sodium atoms is an example of a displacement reaction. For each of the two water molecules, one sodium atom (shown as a blue ball labeled “Na”) kicks one hydrogen atom (shown as a gray ball labeled “H”) out of the water molecule. Then the sodium atom combines with the remaining oxygen atom and hydrogen atom (called a hydroxide [hī-dräk’-sīd] ion) to make a new molecule called sodium hydroxide. Hydrogen gas is formed by the two hydrogen atoms that were kicked out of the two water molecules by the sodium atoms.


3.5 Exchange Reaction

The fourth type of general chemical reaction is the exchange reaction. In this reaction, the atoms of one molecule trade places with the atoms of another molecule to form two new molecules.

The reaction of hydrochloric acid (HCl) and sodium hydroxide (NaOH) is an example of an exchange reaction. The hydrogen atom in the HCl molecule trades places with the sodium atom in the NaOH molecule to make two new molecules, sodium chloride (table salt) and water.

These are the basic types of simple chemical reactions. Some reactions that have many components are much more complicated than those outlined in this chapter, but most chemical reactions fall into one of these four categories.

3.6 Spontaneous or Not?

Not all chemical reactions are spontaneous (spän-tā’-nē-ǝs). Spontaneous means the reaction happens all by itself, just by mixing the chemicals. The exchange reaction of hydrochloric acid (HCl) and sodium hydroxide (NaOH) is a spontaneous reaction; however, not all chemical reactions are spontaneous. The decomposition reaction of water into hydrogen gas and oxygen gas is not a spontaneous reaction. It requires either high heat or an electric current. It’s a good thing that not all reactions occur spontaneously. Imagine how difficult it would be to swim or sail a boat or even get a drink, if water spontaneously decomposed into hydrogen gas and oxygen gas!


3.7 Evidences of Chemical Reactions

To determine whether or not a chemical reaction has occurred, chemists look for certain signs, or evidences, of a change.

There are several signs that tell scientists when a chemical reaction has occurred.

A chemist may look for bubbles being released when something gets added to something else. Bubbles indicate that a gas formed during the reaction.

Or, if two solutions are mixed, the resulting new solution might change color.

Sometimes when two solutions are mixed, a temperature change occurs, and the solution gets either hotter or colder.

Finally, another indication that a chemical reaction has taken place is the formation of a precipitate (pri-si’-pǝ-tāt), which can look like colored sand, mud, dust, or snow forming in a solution. A precipitate forms when the new molecules being made from the chemical reaction do not dissolve in the solution.

These are some of the ways that chemists can tell when a chemical reaction has taken place.


3.8 Summary

Here are the most important points to remember from this chapter:

• A chemical reaction occurs whenever bonds between atoms and molecules are created or destroyed.

• There are different kinds of chemical reactions. They are as follows: combination reactions where molecules join decomposition reactions where molecules break apart displacement reactions where atoms are removed from molecules

exchange reactions where atoms of one molecule trade places with atoms of another molecule

• Not all chemical reactions occur spontaneously.

• Sometimes changes occur that indicate a chemical reaction has taken place. These changes include bubble formation, color changes, temperature changes, and the formation of precipitates (precipitation).

Laboratory Workbook

Rebecca W. Keller, PhD

Cover design: David KellerOpening page: David Keller, Rebecca W. Keller, PhDIllustrations: Rebecca W. Keller, PhD

Copyright ©2013 Gravitas Publications, Inc.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher.

Focus On Middle School Chemistry Laboratory WorkbookISBN: 978-1-936114-60-3


Printed in the United States

Introduction iii

Keeping a Laboratory NotebookA laboratory notebook is essential for the experimental scientist. In this type of notebook, the results of all the experiments are kept together along with comments and any additional information that is gathered. For this curriculum, you should use this workbook as your laboratory notebook and record your experimental observations and conclusions directly on its pages, just as a real scientist would.

The experimental section for each chapter is pre-written. The exact format of a notebook may vary among scientists, but all experiments written in a laboratory notebook have certain essential parts. For each experiment, a descriptive but short Title is written at the top of the page along with the Date the experiment is performed. Below the title, an Objective and a Hypothesis are written. The objective is a short statement that tells something about why you are doing the experiment, and the hypothesis is the predicted outcome. Next, a Materials List is written. The materials should be gathered before the experiment is started.

Following the Materials List is the Experiment. The sequence of steps and all the details for performing the experiment are written beforehand. Any changes made during the experiment should be written down. Include all information that might be of some importance. For example, if you are to measure 237 ml (1 cup) of water for an experiment, but you actually measured 296 ml (1 1/4 cup), this should be recorded. It is hard sometimes to predict the way in which even small variations in an experiment will affect the outcome, and it is easier to track a problem if all of the information is recorded.

The next section is the Results section. Here you will record your experimental observations. It is extremely important that you be honest about what is observed. For example, if the experimental instructions say that a solution will turn yellow, but your solution turned blue, you must record blue. You may have done the experiment incorrectly, or you might have discovered a new and interesting result, but either way, it is very important that your observations be honestly recorded.

Finally, the Conclusions should be written. Here you will explain what the observations may mean. You should try to write only valid conclusions. It is important to learn to think about what the data actually show and also what cannot be concluded from the experiment.

iv Focus On Middle School Chemistry Laboratory Workbook

Laboratory Safety

Most of these experiments use household items. However, some items, such as iodine, are extremely poisonous. Extra care should be taken while working with all chemicals in this series of experiments. The following are some general laboratory precautions that should be applied to the home laboratory:

Never put things in your mouth without explicit instructions to do so. This means that food items should not be eaten unless tasting or eating is part of the experiment.

Use safety glasses while working with glass objects or strong chemicals such as bleach.

Wash hands before and after handling chemicals.

Use adult supervision while working with iodine and while conducting any step requiring a stove.

ContentsExperiment 1: What Is It Made Of? 1 Review 6

Experiment 2: Making Marshmallow Molecules 7 Review 12

Experiment 3: Identifying Chemical Reactions 13 Review 17

Experiment 4: Making an Acid-Base Indicator 18 Review 22

Experiment 5: Vinegar and Ammonia in the Balance: An Introduction to Titrations 23 Review 28

Experiment 6: Mix It Up! 29 Review 33

Experiment 7: Black Is Black? 34 Review 38

Experiment 8: Show Me the Starch! 39 Review 42

Experiment 9: Gooey Glue 43 Review 47

Experiment 10: Amylase Action 48 Review 51

Experiment 1: What Is It Made Of? 1

Experiment 1: What Is It Made Of? Date:

Objective To become familiar with the periodic table of elements and investigate the composition of some common items

Materials

pen or pencilfood labelsperiodic table of elementsresources (books or online) such as:

dictionary encyclopedia

computer with internet access (optional)

Experiment

Using the periodic table of elements, answer the following questions:A. How many protons does aluminum have? How many electrons?B. What is the symbol for carbon?C. List all the elements that have chemical properties similar to helium.

D. What is the atomic weight of nitrogen? How many neutrons does nitrogen have?

2 Focus On Middle School Chemistry Laboratory Workbook

In the table on the next page, fill in the following information.

� ITEMThink of several different items and write them in the column labeled ITEM. These can be any item, like “tires” or “cereal.” Try to be specific. For example, instead of writing just “cereal,” write “corn cereal” or “sweet, colored cereal.”

� COMPOSITIONIn an encyclopedia, on the food label, or online, look up the composition of the items you have selected, and write this information in the column labeled COMPOSITION. Try to be as specific as possible when identifying the composition. For example, if your cereal contains vitamin C, write “sodium ascorbate” if that name is also listed. Try to identify any elements that are in the compounds you have listed. For example, vitamin C contains the element “sodium.”

� SOURCEWrite the source next to the composition. “Source” means where you got your information; for example, “food label” or “encyclopedia,” or if you got the information online, list the name of the website.


ITEM COMPOSITION SOURCE

1.

2.

3.

4.

5.

6.

7.

8.


Results

Briefly describe what you discovered about the composition of the various items.For example:

Kellogg’s Sugar Smacks cereal contains vitamin C, which is called

sodium ascorbate.


Conclusions

State your conclusions based on the information you collected.For example:

Many cereals contain sodium in the form of salt and vitamin C.


Review

Define the following terms:chemistry

matter

atoms (atomos)

proton

neutron

electron

nucleus

electron cloud

element

atomic weight

Experiment 3: Identifying Chemical Reactions 13

Experiment 3: Identifying Chemical Reactions Date:

Objective In this experiment we will try to identify a chemical reaction by observing the changes that occur when two solutions are added together.

Hypothesis A chemical reaction can be identified by observing changes that occur in the course of the reaction.

Materials

baking sodalemon juicebalsamic vinegarsalt and water: 15-30 ml salt dissolved in 120 ml water (1-2 tbsp. salt dissolved in 1/2 cup of water)egg whitesmilkseveral small jarsmeasuring cups and spoonseye dropper

Experiment

Look at the chart in the Results section. Write down all of the substances (baking soda, lemon juice, balsamic vinegar, salt water, egg whites, and milk) horizontally with one item above each column.

Now write the same list of items vertically down the left side of the grid, next to each row.

There should be an item assigned to each column and to each row. In the white boxes of the chart on the next page, record what you

observe when the item listed in the column is mixed with the item in the corresponding row.


Look especially for changes that indicate a chemical reaction has taken place. For example, look for bubbles, color change, or a precipitate.

Ask your teacher for unknown solutions. When you mix them, try to determine whether a chemical reaction has taken place. Try to identify what the unknown solutions are.

Results


Results for Unknown Solutions

Description of each unknown solution:

Results when the two are mixed:

What might they be?


Conclusions


Review

What are the four types of chemical reactions?

Define the following terms:

chemical reaction

combination reaction

decomposition reaction

displacement reaction

exchange reaction

spontaneous

List four signs that may be observed that indicate a chemical reaction has occurred.

Teacher’s Manual


Cover design: David KellerOpening page: David Keller, Rebecca W. Keller, PhDIllustrations: Rebecca W. Keller, PhD

Copyright © 2013 Gravitas Publications, Inc.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher.

Focus On Middle School Chemistry Teacher’s ManualISBN 978-1-936114-61-0


Printed in United States

iiiFOCUS ON MIDDLE SCHOOL CHEMISTRY TEACHER’S MANUALIntroduction

A Note From the AuthorThis curriculum is designed to give students both solid science information and hands-on experimentation. The middle school material is geared toward fifth through eighth grades, but much of the information in the text is very different from what is taught at this grade level in other textbooks. I feel that students beginning with the fifth grade can grasp the concepts presented here. This is a real science text, so scientific terms are used throughout. It is not important at this time for students to master the terminology, but it is important that they be exposed to the real terms used to describe science.

For students, each chapter has two parts: a reading part in the Focus On Middle School Chemistry Student Textbook and an experimental part in the Focus On Middle School Chemistry Laboratory Workbook. In this teacher’s manual, an estimate is given for the time needed to complete each chapter. It is not important that both the reading portion and the experimental portion be concluded in a single sitting. It may be better to have students do these on two separate days, depending on the interest level of the child and the energy level of the teacher. Also, questions not addressed in the Teacher’s Manual may arise, and extra time may be required to investigate these questions before proceeding with the experimental section.

Each experiment is a real science experiment and not just a demonstration. They are designed to engage students in an actual scientific investigation. The experiments are simple but are written the way real scientists actually perform experiments in the laboratory. With this foundation, it is my hope that students will eventually begin to think of their own experiments and test their own ideas scientifically.

Enjoy!


iv FOCUS ON MIDDLE SCHOOL CHEMISTRY TEACHER’S MANUALIntroduction

How To Use This Manual

Each chapter in this Focus On Middle School Chemistry Teacher’s Manual begins by providing additional information for the corresponding chapter in the student textbook. This supplementary material is helpful when questions arise while students are reading the text. It is not necessary for students to learn this additional material since most of it is beyond the scope of this level. However, the teacher may find the information helpful when answering questions.

The second part of each chapter in the Teacher’s Manual provides directions for the experiments in the Laboratory Workbook as well as answers to the questions asked in each experiment and review section. All of the experiments have been tested, but it is not unusual for an experiment to produce an unexpected outcome. Usually repeating an experiment helps both student and teacher see what might have occurred during the experimental process. Encourage the student to troubleshoot and investigate all possible outcomes. However, even repeating an experiment may not produce the expected outcome. Do not worry if an experiment produces a different result. Scientists don’t always get the expected results when doing an experiment. The important thing is for students to learn about the scientific method and to make observations, think about what is taking place, and ask questions.

Getting StartedThe experimentation process will be easiest if all the materials needed for the experiment are gathered together and made ready before beginning. It can be helpful to have a small shelf or cupboard or even a plastic bin dedicated to holding most of the necessary chemicals and equipment. The following Materials at a Glance chart lists all of the materials needed for each experiment. An additional chart lists the materials by type and quantity. A materials list is also provided at the beginning of each lesson.

vFOCUS ON MIDDLE SCHOOL CHEMISTRY TEACHER’S MANUALIntroduction

Materials at a Glance

Experiment 6

Experiment 7

Experiment 8

Experiment 9

Experiment 10

waterammoniavegetable oilrubbing alcoholmelted buttervinegarsmall jars (7 or

more)food coloringdish soapeye droppermeasuring spoonsmeasuring cupmarking pen(See next page for

materials for optional activity)

ballpoint ink pens (various colors)

black ballpoint ink pen

rubbing alcoholcoffee filters (white)several small jarscardboard shoe boxtapemeasuring cupscissorsruler

tincture of iodine (from Walgreen’s or other pharmacy)

raw food items: pasta, bread, celery, potato, banana, apple, etc.

liquid laundry starch

absorbent white paper

eye droppercookie sheetmarking pen

liquid laundry starch (or Borax)

Elmer’s white glueElmer’s blue glue

(or another glue different from white glue)

water2 small jarsmarking penPopsicle sticks for

stirringmeasuring spoons

tincture of iodine (from Walgreen’s or other pharmacy)

breadtimerwax papermarking pencup

Experiment 1

Experiment 2

Experiment 3

Experiment 4

Experiment 5

penlabels from food

productsperiodic table of

elements (from Focus on Middle School Chemistry Textbook)

books or online: dictionary encyclopedia


small, colored marshmallows

large marshmallowsoptional

replacements for marshmallows: gumdrops or jelly beans

toothpicks

baking sodalemon juicebalsamic vinegarsalt (1-2 Tbsp.

dissolved in 1/2 cup of water)

egg whitesmilkseveral small jarsmeasuring cupsmeasuring spoonseye dropper(See next page for

materials for optional activity)

one head red cabbage

distilled waterammoniavinegarsoda popmilkmineral waterlarge saucepanknifesmall jarscoffee filters (white)eye droppermeasuring cupmeasuring spoonsmarking penscissorsruler

red cabbage indicator (from Experiment 4)

household ammoniavinegarlarge glass jarmeasuring spoonsmeasuring cup

vi FOCUS ON MIDDLE SCHOOL CHEMISTRY TEACHER’S MANUALIntroduction

Materials at a GlanceBy type with total quantities

Equipment Materials (cont.) Food Items Just For Fun


cookie sheetcupeye dropperjar, large glassjars, small, 7 or moremeasuring cupsmeasuring spoonsrulersaucepan, largescissorstimer

glue, Elmer’s blue (or another glue different from white glue), 60 ml [1/4 cup]

glue, Elmer’s white, 60 ml [1/4 cup]

iodine, tincture of (from Walgreen’s or other pharmacy), several droppers

laundry starch, liquid (or 30 ml [2 Tbsp] each of borax and cornstarch)

paperpaper, absorbent whitepaper, waxpenpens, inexpensive

ballpoint (1 each: black, blue, red, green, etc.) or multicolored pen with 7-8 colors

pen, markingpencilperiodic table of elements

(from Focus On Middle School Chemistry Student Textbook)

rubbing alcohol, 135 ml [1/2 cup]

sticks, Popsicle, severaltapetoothpicks, 1 pkg

baking soda, 15-30 ml [1-2 Tbsp.]

breadbutter, 75 ml [1/3 cup]cabbage, red (one head)egg whites (1 or 2)food coloringgumdrops (optional

replacement for marshmallows), 1 pkg

jelly beans (optional replacement for marshmallows), 1 pkg

lemon juice, 15-30 ml [1-2 Tbsp.]

marshmallows, large, 1 pkg

marshmallows, small, colored, 1 pkg

milk, 420 ml [1 3/4 cup]raw foods

(1 or 2 pieces each): pasta bread, 2 slices celery potato banana other fruits

salt, 15-30 ml [1-2 Tbsp.]soda pop, 15 ml [1 Tbsp.]vegetable oil, 90 ml [3/8

cup]vinegar, 345 ml [1.5 c.]vinegar, balsamic, 15-30

ml [1-2 Tbsp.] optional, but recommended

water, distilled, 1.1 liter [4.5 cups]

water, mineral, 15 ml [1 Tbsp]

water, tap

Optional Activities

Exper. 3: Peanut Brittle360 ml (1 1/2 cups) sugar240 ml (1 cup) white corn

syrup120 ml (1/2 cup) water360 ml (1 1/2 cups) raw

peanuts5 ml (1 teaspoon) baking

sodasauce panbuttered pan

Exper. 6: Easy Chocolate Cake

710 ml (3 cups) flour470 ml (2 cups) sugar120 ml (1/2 cup) cocoa5 ml (1 tsp) salt 175 ml (3/4 cup) shortening2 eggs240 ml (1 cup) buttermilk240 ml (1 cup) boiling water10 ml (2 teaspoons) baking

sodasaucepanmixing bowlmixing spoon or mixer3 layer-cake pans

Materials

Focus On Middle School Chemistry Laboratory Workbook

ammonia, 200 ml [1 cup]box, cardboard shoe box

or similar sizecoffee filters,white

(several)dictionary (book or

online)dish soap, 45 ml [3 Tbsp.]encyclopedia (book or

online)labels from food products

viiFOCUS ON MIDDLE SCHOOL CHEMISTRY TEACHER’S MANUALIntroduction

Laboratory SafetyMost of these experiments use household items. However, some substances, such as iodine, are extremely poisonous. Extra care should be taken while working with all chemicals in this series of experiments. The following are some general laboratory precautions that should be applied to the home laboratory:

• Never allow students to put things in their mouth unless the experiment instructs them to do so. This means that food items should not be eaten unless tasting or eating is part of the experiment.

• Have students use safety glasses while working with glass objects or strong chemicals such as bleach.

• Have students wash their hands after handling all chemicals.

• Provide adult supervision while students are working with iodine or glassware and while conducting any step requiring a stove.

ContentsChapter 1: Matter 1 Experiment 1: What Is It Made Of? 6 Review of Terms 9

Chapter 2: Molecules 10 Experiment 2: Making Marshmallow Molecules 14 Review of Terms 19

Chapter 3: Chemical Reactions 20 Experiment 3: Identifying Chemical Reactions 24 Review of Terms 27

Chapter 4: Acids, Bases, and pH 28 Experiment 4: Making an Acid-Base Indicator 32 Review of Terms 35

Chapter 5: Acid-Base Neutralization 36 Experiment 5: Vinegar and Ammonia in the Balance: An Introduction to Titrations 40 Review of Terms 44

Chapter 6: Mixtures 45 Experiment 6: Mix It Up! 49 Review of Terms 53

Chapter 7: Separating Mixtures 54 Experiment 7: Black Is Black? 58 Review of Terms 62

Chapter 8: Energy Molecules 63 Experiment 8: Show Me the Starch! 67 Review of Terms 70

Chapter 9: Polymers 71 Experiment 9: Gooey Glue 75 Review of Terms 79

Chapter 10: Biological Polymers: Proteins and DNA 80 Experiment 10: Amylase Action 85 Review of Terms 87

Chapter 1: Matter

Overall Objectives 2

1.1 Introduction 2

1.2 Atoms 2

1.3 Periodic Table 3

1.4 Summary 5


Conclusions 8

Review 9

Time Required

Text reading 30 minutes Experimental 1 hour

Materials

pen or pencillabels from food productsperiodic table of elements

(from Focus On Middle School Chemistry Student Textbook)resources (books or online) such as:



2 FOCUS ON MIDDLE SCHOOL CHEMISTRYTeacher’s Manual

Overall Objectives

This chapter introduces the concept that all things, living and nonliving, are made of the same fundamental components called atoms. It is important to help students understand that although the world is full of a large number of both living and nonliving things, there is only a limited number of atoms, or elements, that make up all things. The variety observed in all things is a result of the vast number of ways that atoms can be combined with one another. For example, sodium (Na) is combined with chlorine (Cl) to make sodium chloride (NaCl) which is table salt. However, if you add an oxygen atom (O) to make sodium hypochlorite, NaOCl, you get bleach.

1.1 Introduction

Matter is a general term for the substance of which all things are composed.

Chemistry is that area of science mainly concerned with the ways in which atoms combine to form chemical bonds.

There are several different subdisciplines within chemistry:

• Physical chemistry is concerned with the fundamental physics of atoms.

• Biochemistry is concerned with matter that makes up living things.

• Organic chemistry is concerned with the chemistry of carbon containing compounds.

• Analytical chemistry deals with analyzing the composition of matter.

• Inorganic chemistry is concerned mostly with non-carbon compounds.

1.2 Atoms

Students will be introduced to the following terms:

• Atoms• Protons• Neutrons• Electrons

Atoms, protons, neutrons and electrons are more specific terms for matter.

Atoms are very small and cannot be seen by the naked eye. If an atom were the size of a tennis ball, the average man (6 ft. tall) would stand one million kilometers high—almost the distance from here to the Sun.

CHAPTER 1Matter

3

Protons and neutrons are roughly equal in size, and both have an atomic mass of 1 amu (atomic mass unit). A proton carries a positive charge, and a neutron carries no charge—it is neutral. By comparison, the electron is 1/1836 of the mass of a proton. The electron carries a negative charge that is equal in magnitude to the charge on a proton. For neutral atoms, the number of electrons equals the number of protons. The number of neutrons does not always equal the number of protons or electrons in neutral atoms.

The nucleus contains the protons and neutrons and is much smaller than the full atom. Most of the volume of an atom is occupied by the electrons.

The space occupied by the electrons surrounds the proton-neutron core and is called an orbital or electron cloud. Orbitals can have a variety of shapes, and the different shapes of electron clouds are very important for understanding how atoms combine with each other. (This will be covered in the textbook for the next level.)

1.3 Periodic Table

The periodic table of elements is a large chart that organizes and categorizes all of the elements according to their chemical properties.

The periodic table illustrates the general law of periodicity among all of the elements. This means that certain chemical properties of the atoms repeat. For example, fluorine (F) undergoes chemical reactions similar to those of chlorine (Cl), bromine (Br), iodine (I), and astatine (At). All of these similar elements are arranged in a single column of the periodic table. Grouping the elements according to their chemical properties gives rise to the “periods” which are the horizontal rows.

There are three short periods of 2, 8, and 8 elements:

• hydrogen -> helium [period of 2 elements]• lithium -> neon [period of 8 elements]• sodium -> argon [period of 8 elements]

and then three longer periods of 18, 18, and 32:

• potassium -> krypton [period of 18 elements]• rubidium ->xenon [period of 18 elements]• cesium ->radon [period of 32 elements]

The final period is predicted to contain 32 elements, but notice that the last elements are as yet undiscovered.

The last naturally occurring element is uranium with 92 protons. The elements after uranium are artificially made.


The symbols of the elements are not always the same as the first letter or two of the English name since some elements were named in other languages. Examples are given in the student textbook.

The following details of the periodic table are explained briefly in the textbook.

The number in the upper left-hand corner of each element square is the atomic number. This number tells how many protons the atom contains. The atomic number is not always in the upper-left-hand corner of the block representing the element—it can be in the middle or on the right.

The number below the name of the element is the atomic weight. The atomic weight is the sum of the weight of the protons, neutrons, and electrons. Because the electrons have essentially no mass, the atomic weight can be considered to be the sum of just the weight of the protons and neutrons. Because protons and neutrons are essentially 1 atomic mass unit each, the number of neutrons can be determined by subtracting the atomic number from the atomic weight.

Examples:Hydrogen has an atomic number of 1. This means that hydrogen has one proton. Also, hydrogen has an atomic weight close to one, which means that all of the weight is due to the single proton. There are no neutrons.

Another example is uranium:

number of protons: 92 atomic weight: 238 number of neutrons: 238 minus 92 = 146

NOTE: Although the atomic weight is actually 238.0289, it is rounded to 238 to calculate the number of neutrons.

The elements are organized vertically in the periodic table according to similar chemical properties.

The elements on the far right of the periodic table are the noble gases. In general, the noble gases do not react with other elements. It is possible to get some of the noble gases to react, but it is very difficult. The noble gases are always found in nature as single atoms and not in pairs like other gases such as oxygen and nitrogen.

The elements on the far left are called the alkali metals. These elements are very reactive. Lithium (Li), sodium (Na), and potassium (K) react very violently with water. They also form salts with the halogens, which form the column to the left of the noble gases. Some common salts include sodium chloride (NaCl), lithium chloride (LiCl), and potassium chloride (KCl). Sodium chloride (NaCl) is common table salt. Potassium chloride (KCl) is a table salt alternative that is used by many people with high blood pressure.

CHAPTER 1Matter

5

There are other “trends” or properties that are illustrated in the periodic table, such as atomic size and electronegativity, and these will be introduced later.

The most important points to emphasize about the periodic table are the following:

• All of the elements that make up all things, living and nonliving, are in the periodic table.

• The periodic table illustrates an underlying order or “periodicity” among all of the elements.

• Mendeleev discovered the overall order of elements through scientific investigation and assembled the first periodic table.

1.4 Summary

Discuss with the students the main points of this chapter.

• Point out that everything we can touch is made of atoms. Have the students name several different items and discuss how these items are all made of atoms.

• Review that atoms are made of smaller particles called protons, neutrons, and electrons. Protons and neutrons form the atomic core, or nucleus, and electrons are found in the electron cloud surrounding the nucleus.

• Review that the number of protons equals the number of electrons in an atom. This is true for neutral atoms. It is possible to remove an electron from an atom or add an electron to an atom. The atom is then called an ion and has a positive or negative charge. (This will be discussed in the textbook for the next level.)

• All of the elements known are found in the periodic table of elements. New elements can be made artificially, but all naturally occurring elements are already known.

• Review that in the periodic table all of the elements are in groups that are similar. For example, the noble gases behave similarly and are in the same column.


The goals of this experiment are to help students begin to investigate the things in their world and to have them start to examine what those things are made of.

There are many possible answers for this experiment. By using basic resources such as the dictionary or encyclopedia, students may not be able to find the elemental composition of all the items they think of.

Some examples of answers are the following:

Things made of metals:• soda cans and aluminum foil -

aluminum• silverware (steel) - iron, nickel,

silver• coins - copper, nickel• jewelry - gold, silver

Things we eat:• salt - sodium and chlorine• sugar - carbon, oxygen, hydrogen• water - hydrogen and oxygen• bread (carbohydrates) - carbon,

oxygen, hydrogen, and other proteins and things

Also, students can select food items with labels, such as cake mixes, cereal, noodles, and vitamins (with vitamins the label is very detailed so students can also find out how much of something is in the vitamin).

Students DO NOT need to find every component for each item. To say that cake mix contains salt, flour, and sugar is enough. Let the students go as far as they want to with a particular item. Also, it is not necessary to look up components for each item the students think of. Pick a few and go from there.

Experiment 1: What Is It Made Of? Date:

Objective To become familiar with the periodic table of elements and investigate the composition of some common items

Materialspen or pencilfood labelsperiodic table of elementsresources (books or online) such as:



Experiment Using the periodic table of elements, answer the following questions:

A. How many protons does aluminum have? 13

How many electrons? 13

B. What is the symbol for carbon? C

C. List all the elements that have chemical properties similar to helium.

The elements that have chemical properties that are similar to helium are neon, argon, krypton, xenon, and radon.

D. What is the atomic weight of nitrogen? 14.0067

How many neutrons does nitrogen have? 7 neutrons

In the table on the next page, fill in the following information. � ITEMThink of several different items and write them in the column labeled ITEM. These can be any item, like “tires” or “cereal.” Try to be specific. For example, instead of writing just “cereal,” write “corn cereal” or “sweet, colored cereal.”

� COMPOSITIONIn an encyclopedia, on the food label, or online, look up the composition of the items you have selected, and write this information in the column labeled COMPOSITION. Try to be as specific as possible when identifying the composition. For example, if your cereal contains vitamin C, write “sodium ascorbate” if that name is also listed. Try to identify any elements that are in the compounds you have listed. For example, vitamin C contains the element “sodium.”

� SOURCEWrite the source next to the composition. “Source” means where you got your information; for example, “food label” or “encyclopedia,” or if you got the information online, list the name of the website.

CHAPTER 1Matter

7

The atomic weight of nitrogen is 14.0067. To calculate the number of neutrons, subtract the number of protons (7) from the atomic weight. 14 - 7 = 7. Nitrogen has 7 neutrons. It has the same number of neutrons as it has protons.

EXPERIMENT A-DAluminum (Al) has 13 protons. This means aluminum has 13 electrons as well.

The symbol for carbon is “C.”

The elements that have the same chemical properties as helium are in the same column in the periodic table.

AlAluminum

13

CCarbon

6

12.011

KrKrypton

F9

RnRadon

36

86

NeNeon

10

HeHelium

2

XeXenon

54

ArArgon

18

NNitrogen

7

14.0067

ITEM COMPOSITION SOURCE

1. graham crackers sodium bicarbonate (sodium) food label

2. graham crackers salt (sodium, chlorine)food label, dictionary- page 1600

3. car tires rubber (carbon and hydrogen)Wikipedia (or www.wikipedia.org)

4.

5.

6.

7.

8.

(Answers may vary.)


Conclusions

(Answers may vary.)

State your conclusions based on the information you collected.

For example:

Many cereals contain sodium as part of salt and vitamin C.

Some peanut butter contains sugar.

Rubber contains carbon and hydrogen.

Results

(Answers may vary.)

Briefly describe what you discovered about the composition of the various items.

For example:

Kellogg’s Sugar SmacksTM cereal contains vitamin C, which is called

sodium ascorbate.

Table salt is made of sodium and chlorine.

Iodized table salt contains sodium, chlorine, and iodine.

Chocolate cake mix contains sugar.

Sugar has oxygen, hydrogen, and carbon in it.

Help the students write accurate statements about the data they have collected. Some examples are given.

Next, help the students think specifically about what their data show. This is an important critical thinking step that will help them evaluate future experiments.

Try to help them write concluding statements that are valid. Encourage them to avoid stating opinions or any conclusions that cannot be drawn strictly from their data.

For example, it may be true that all cereals contain salt. However, this particular investigation cannot confirm or deny that conclusion. The most that can be stated from this investigation is “Brand X contains salt and Brand Y contains salt,” but any further statement is conjecture.

Help them formulate their conclusions using the words some, all, many, and none. Point out that the statement, “All cereals contain salt,” is not valid, but based on this investigation, it is valid to say, “Some cereals contain salt.”

Again, there are numerous possible answers. One student may list “sugar” as a component in soup, and another may list “salt,” and both answers could be correct. The true test is whether the statements about the data are valid or not valid.

Also, try to show students where broad statements can be made validly. For example, “All recent U.S. pennies contain copper” is probably a valid statement even though we haven’t checked every U.S. penny.

This may seem fairly subtle, but the main point is to help them understand the kinds of valid conclusions science can offer based on scientific investigation.

CHAPTER 1Matter

9

ReviewDefine the following terms:

(Answers may vary.)

chemistry a branch of science concerned with the properties of matter

matter a general term for what makes up all things

atoms (atomos) the fundamental building blocks of matter. Atomos is a Greek word that means uncuttable

proton a small particle found inside atoms

neutron another small particle found inside atoms

electron a particle found in an atom that is very much smaller than both protons and neutrons

nucleus the central portion of an atom that consists of only the protons and neutrons

electron cloud the space occupied by the electrons surrounding the nucleus

element another name for any of the distinct atoms in the periodic table

atomic weight the total weight of an atom; the weight of the protons and neutrons combined

Chapter 3: Chemical Reactions

Time Required

Text reading 1 hour Experimental 1 hour

Materials

baking soda water lemon juice several small jars balsamic vinegar eye dropper salt measuring cup egg whites measuring spoons milk

Overall Objectives 21

3.1 Introduction 21

3.2 Combination Reaction 21

3.3 Decomposition Reaction 21

3.4 Displacement Reaction 22

3.5 Exchange Reaction 22

3.6 Spontaneous or Not? 22

3.7 Evidences of Chemical Reactions 22

3.8 Summary 23


Conclusions 26

Review 27

Just For Fun—Peanut Brittle

360 ml (1 1/2 cups) sugar 240 ml (1 cup) white corn syrup 120 ml (1/2 cup) water 360 ml (1 1/2 cups) raw peanuts 5 ml (1 teaspoon) baking soda sauce pan buttered pan

CHAPTER 3Chemical Reactions

21

Overall Objectives

In this chapter students will begin to learn how atoms and molecules react to form and break chemical bonds. It is not important for the students to memorize the names of the reactions. Help them understand that in chemical reactions the atoms are rearranged. Electrons can be swapped back and forth between atoms, but the protons and neutrons remain in their original nucleus.

3.1 Introduction

Point out to the students that chemical reactions occur everywhere.

For example:

• Stomach acid helps to digest our food.• When hair is straightened or permed, sulfur bonds are broken and

reformed.• Cars are powered by the combustion (chemical reaction) of gasoline

with oxygen from the air.• When iron is left outside it reacts with oxygen and rust forms.

Four main divisions of chemical reactions are given. These are called combination reactions, decomposition reactions, displacement reactions, and exchange reactions. Most chemical reactions fall into these categories or are combinations of these categories.

3.2 Combination Reaction

In a combination reaction, two or more molecules combine to form a single product. The example shown is the formation of sodium chloride (table salt) by combining sodium metal and chlorine gas.

NOTE: In the reaction between sodium metal and chlorine gas, the chlorine gas is a dimer (two atoms of chlorine). The bond between the chlorine atoms is broken before the formation of sodium chloride, so there is an additional step that is not shown.

3.3 Decomposition Reaction

In a decomposition reaction, molecules decompose or “break down” to form other molecules.

Note that two molecules of water decompose into one molecule of oxygen gas and two molecules of hydrogen gas. This is called a balanced reaction, because the number of H and O atoms is the same before and after the reaction—only the bonds change.


3.4 Displacement Reaction

A displacement reaction is slightly harder to visualize than the other two reactions because bonds are breaking and reforming at the same time. In the reaction of water with sodium metal, the sodium atoms displace a hydrogen atom on each of the water molecules. The two free hydrogens then combine to make hydrogen gas (H2 ).

Note that this reaction is balanced because two water molecules react with two sodium atoms giving two molecules of sodium hydroxide (NaOH) and one molecule of hydrogen gas; thus, the same number and kind of atoms are present before and after the reaction.

3.5 Exchange Reaction

In an exchange reaction, the atoms trade places. The example shown is the reaction of hydrochloric acid (HCl) and sodium hydroxide (NaOH). Again, bonds are both breaking and forming in this reaction.

This particular exchange reaction is also an acid-base reaction and will be covered in more detail in subsequent chapters. Hydrochloric acid is a very strong acid and very harmful if swallowed. Sodium hydroxide is a very strong base and also very harmful if swallowed. Both of these will also cause burns on skin. However, when they are added together and react, they make table salt (which we eat) and water. If concentrated reagents (chemical substances) are used, the reaction is quite violent and will produce a large amount of heat.

3.6 Spontaneous or Not?

Not all reactions occur spontaneously. Some reactions, like the decomposition of water, require energy input before the reaction will proceed. The reasons why one reaction is spontaneous and another is not are beyond the scope of this level. The key concepts are “enthalpy” and “entropy.” These are described in a branch of chemistry called chemical thermodynamics.

3.7 Evidences of Chemical Reactions

There are several indicators that tell scientists when a chemical reaction has taken place. These include bubbles, color change, heat exchange, and precipitation. Sometimes more than one of these can occur at the same time. For example, both bubbles and heat can be given off together. Sometimes none of them occur, and more subtle methods must be used to detect the reaction.

Bubbles form when one of the molecules produced is a gas.

Color changes may indicate a variety of end products. Compounds that contain metals, like copper (Cu), often display color. Blood, for example,


23

contains iron (Fe). When blood is combined with oxygen, it is bright red; however, without oxygen it is a darker red.

A solution can either give off heat (exothermic reaction) or take in heat (endothermic reaction). Most exothermic reactions are spontaneous.

Precipitations occur when one or more products of the reaction are no longer soluble in the solution.

3.8 Summary

Discuss with the students the following main points of this chapter:

• Molecules and atoms react with each other to form new molecules.

• There are four basic types of chemical reactions, and these can combine to make more complex reactions.

• Not all reactions occur spontaneously.• Some chemical reactions can be observed.


In this experiment the students will examine chemical reactions and try to identify when they occur.

Balsamic vinegar is recommended because the reaction when it is mixed with baking soda will be more dramatic, but other kinds of vinegar may be used.

Have the students put a small amount of each substance listed into its own jar, and then have them examine the contents of each jar, taking note of the properties of each substance.

Have them record the color, texture, and odor next to each item on the materials list wherever possible. For example:

• Baking Soda: white powder, no odor

• Balsamic Vinegar: dark liquid, sour odor

Although most of the items are food items, do not allow the students to taste them since tasting is not part of this experiment.

A variety of food items in addition to those on the materials list may be used. Bleach and ammonia cause good chemical reactions, but they can give off strong odors and so neither of these chemicals is recommended.

Experiment 3: Identifying Chemical Reactions Date:

Objective In this experiment we will try to identify a chemical reaction by observing the changes that occur when two solutions are added together.

Hypothesis A chemical reaction can be identified by observing changes that occur in the course of the reaction.

Materialsbaking sodalemon juicebalsamic vinegarsalt and water: 15-30 ml salt dissolved in 120 ml water (1-2 tbsp. salt

dissolved in 1/2 cup of water)egg whitesmilkseveral small jarsmeasuring cups and spoonseye dropper

Experiment Look at the chart in the Results section. Write down all of the

substances (baking soda, lemon juice, balsamic vinegar, salt water, egg whites, and milk) horizontally with one item above each column.

Now write the same list of items vertically down the left side of the grid, next to each row.

There should be an item assigned to each column and to each row. In the white boxes of the chart on the next page, record what you

observe when the item listed in the column is mixed with the item in the corresponding row.


25

Have the students write the “reagents” (chemicals used in chemical reactions) on the top and side of the grid provided.

Have them mix some of each of two substances together in a clean jar and observe the results. It might be interesting to the students to check the order of addition—add lemon juice to baking soda, then add baking soda to lemon juice—to see if a difference can be observed (the order of addition should not matter). This is optional.

Have the students record their observations in the appropriate box for each reaction.

Look especially for changes that indicate a chemical reaction has taken place. For example, look for bubbles, color change, or a precipitate.

Ask your teacher for unknown solutions. When you mix them, try to determine whether a chemical reaction has taken place. Try to identify what the unknown solutions are.

Results

milklemonjuice

salt water

bakingsoda

balsamicvinegar

eggwhites

milk

lemonjuice

salt water

bakingsoda

balsamic vinegar

eggwhites

REACTprecipitate

NO NO REACTprecipitate

NO

NO REACTbubbles

NO REACTprecipitate

NO NO NO

REACTbubbles

NO

REACTprecipitate


Give the students two “unknown” solutions. These can either be two that will react or two that won’t react. This part of the experiment can be done more than once. The students may want to give you “unknowns” to see if you can identify them.

Explain to the students that much of the time scientists are trying to figure out how to identify unknowns. The students have observed all of the reactants both before and after a reaction. They now have the necessary knowledge to identify an unknown.

Another option is to give the students only one unknown. Have them guess what it might be before performing any tests. Then have the students test this unknown with each of the other reactants. Have them prove the identity of the unknown with the chemical reactions they have already observed.

Have the students write valid conclusions. Help them state conclusions that reflect only the data found in this experiment. For example, “Salt water does not react with anything” is not a valid conclusion because we haven’t tested everything. However, “Salt water does not react with any of the items we tested” is valid.

Conclusions

Results for Unknown SolutionsDescription of each unknown solution:

Results when the two are mixed:

What might they be?


27

Review

(Answers may vary.)

What are the four types of chemical reactions?

decomposition reaction

combination reaction

displacement reaction

exchange reaction

Define the following terms:

chemical reaction a process in which chemical bonds are broken or created between atoms and molecules

combination reaction a reaction in which two molecules combine to form a single product

decomposition reaction a reaction in which a molecule breaks apart to make two or more new molecules

displacement reaction a reaction in which one atom removes another atom from a molecule

exchange reaction a reaction in which one atom trades places with another atom in a different molecule

spontaneous term describing when a reaction happens all by itself

List four signs that may be observed that indicate a chemical reaction has occurred.

bubbles forming

color change

temperature change

precipitate formation

Just For FunWatch baking soda decompose and give off carbon dioxide gas while peanut brittle is being made.

Peanut Brittle360 ml (1 1/2 cups) sugar

240 ml (1 cup) white corn syrup

120 ml (1/2 cup) water

360 ml (1 1/2 cups) raw peanuts

5 ml (1 teaspoon) baking soda

buttered pan

Boil sugar, water, and syrup in a sauce pan over medium heat until the mixture turns a little brown. Add 360 ml (1 1/2 cups) raw peanuts Stir until golden brown. Don’t over-brown. Add 5 ml (1 teaspoon) baking soda. Spread on buttered pan.

Middle School Lesson Plan


Focus On Middle School

Chemistry

Middle School Lesson Plan


All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. No part of this book may be used or reproduced in any manner whatsoever without written permission.

Focus On Middle School Chemistry Lesson Plan


FOCUS ON MIDDLE SCHOOL CHEMISTRY LESSON PLAN

OverviewTeaching Real Science-4-Kids is as easy as 1-2-3.

1. Introduce content.

2. Perform an experiment.

3. Make connections.

RS4K comes in easy-to-use modules that focus on a particular subject. Each subject module is designed to introduce your child to one of the foundational building blocks of science. Once your child has been introduced to these foundational subjects, he or she can build their science education from the ground up, understanding, mastering, and quickly learning new science information.

The lesson planThis is a weekly lesson plan that will walk you through the middle school curriculum. There are 20 weeks of instruction for each subject module. You can teach the 20 weeks in one semester or one year depending on the age of your child.

You decide how fast or slow to go with your child. If you are not sure about the pace, start slowly. It is better that your child learns fewer “facts” with more understanding than be overwhelmed by too much information. You also don’t want to slow down an advanced learner. Here is a suggested guideline.

♦ Age 10-11: a subject module (20 weeks) in one year.

♦ Age 12-13: a subject module in one semester, combining two weeks of the Lesson Plan into one week of study.

Each week is divided into three sections: content, experiment, and connections.

1. The content directs your child to learn the scientific “facts” in each subject.

2. The experiment allows your child to learn the steps of the scientific method.

3. Connections between science and language, history, philosophy, technology, and art are explored.

NOTE: You will see chapter suggestions for the Chemistry KOGs. These are supplementary books that contain additional exercises to accompany each chapter of the textbook. If you own the Chemistry KOGs, this lesson plan will help you incorporate them into your teaching sessions. If not, you can still use the questions for open inquiry that you’ll find in this lesson plan.

You can modify the lesson plan as desired. There is no “wrong” way to teach science. Let your child explore, investigate, ask questions, examine, and observe everything they find interesting. The middle school age group is about bringing what they’ve learned through experience and play into a formal scientific framework.

In the Connections section of this Lesson Plan, there are many suggestions for additional study meant to engage you and your child in further explorations of science. These are open inquiry questions, so don’t worry about trying to form “right” answers. Instead, these are suggestions for exploration, and exploration is the first step in learning.

Every chapter has been aligned to the National Science Standards. (taken from the National Science Education Standards (1996) and the Framework for K-12 Science Education (2012) National Academies Press)

Before you begin ♦ Open the teacher’s manuals for the subject modules

you have purchased.

♦ Look at the materials list for each subject module.

♦ Using a large container or bin, collect the non-perishable items from the lists. Organize the items in your container. This will help you be prepared for the experiments for each subject module.

♦ Look through this lesson plan which is easy to use and will help you organize your child’s study.

Need Help?We are here to help you!

We have several support options available.

If you like online communities, we have a Yahoo group that discusses experiments and ideas and even provides contacts for resale of RS4K curriculum.

http://groups.yahoo.com/group/RealScience4Kids/

RS4K has a Facebook Fanpage where you can meet other RS4K users and ask questions directly to Dr. Keller.

http://www.facebook.com/rebecca.w.keller

You can email us and talk to our friendly staff who will be happy to help you with any questions you might have.

[email protected]

Week Chapter

Experiment

Connections

DAY 1

DAY 2

DAY 3

DAY 5

Notes

DAY 4

2 | Real Science-4-Kids

Content Have your child read Chapter 1. Allow open discussion and let your child ask questions. Explore questions using the internet or library.

Have your child perform Experiment 1: What Is It Made Of?

Use the additional information in the Teacher’s Manual to guide the experiment.

1 1 Matter

Discuss the word atom. Have your child do an internet or library search and write the meaning of this word.

Language KOG—Chapter 1

Ask your child about their family history. How far back can they trace their family history? Explore the history of the atom in the same way.

History KOG—Chapter 1

Have your student look up the philosopher Democritus on the internet or at the library. Who was Democritus and what is his story?

Philosophy KOG—Chapter 1

Experiment

Connections

DAY 1

DAY 2

DAY 3

Review DAY 5

Standards

DAY 4

FOCUS ON MIDDLE SCHOOL CHEMISTRY LESSON PLAN | 3

Week Chapter

Discuss the conclusions from Experiment 1.

Discuss and perform any modifi cations for the experiment.

Exam.

Have your student take the Chapter 1 quiz online or print it out.

2 1 Matter

Science as Inquiry - Content Standard A

Th ink critically and logically to make relationships between evidence and explanations.

Physical Science - Content Standard B

Matter exists as diff erent substances (made of atoms).

Science and Technology - Content Standard E

Science and technology are reciprocal. Science helps drive technology and technology is essential to science.

History and Nature of Science - Content Standard G

Science has a history, and people have been studying nature through science for a long time.

From the National Science Education Standards (1996) and the Framework for K-12 Science Education (2012) National Academies Press.

P

P

P

P

Have a discussion about technology and atoms. What technologies do we have today because of the discovery of atoms? How has the discovery of atoms changed our everyday lives?

Technology KOG—Chapter 1

Have a discussion about art and atoms. How does science play a role in the arts?

Art KOG—Chapter 1

Have your student critically evaluate all they have learned this week. How does all of this information contribute to our understanding of atoms?

Critical Thinking KOG—Chapter 1

Week Chapter

Experiment

Connections

DAY 1

DAY 2

DAY 3

DAY 5

Notes

DAY 4

4 | Real Science-4-Kids

Content

5 3 Chemical Reactions

Have your child read Chapter 3. Allow open discussion and let your child ask questions. Explore questions using the internet or library.

Have your child perform Experiment 3: Identifying Chemical Reactions.

Use the additional information in the Teacher’s Manual to guide the experiment.

Have your student look up the philosopher Heraclitus on the internet or at the library. Who was Heraclitus and what is his story?

Philosophy KOG—Chapter 3

Discuss the word combine. Have your child do an internet or library search and write the meaning of this word.

Language KOG—Chapter 3

Ask your child about the history of chemical reactions. Who fi rst discovered the chemical reaction?

History KOG—Chapter 3

Experiment

Connections

DAY 1

DAY 2

DAY 3

Review DAY 5

Standards

DAY 4

FOCUS ON MIDDLE SCHOOL CHEMISTRY LESSON PLAN | 5

Week Chapter6 3 Chemical Reactions

Discuss the conclusions from Experiment 3.

Discuss and perform any modifi cations for the experiment.

Exam.

Have your student take the Chapter 3 quiz online or print it out.

Science as Inquiry - Content Standard A

Science advances through legitimate skepticism. Asking questions and querying other scientists’ explanations is part of scientifi c inquiry.

Physical Science - Content Standard B

Substances react chemically in characteristic ways with other substances to form new substances (compounds) with diff erent characteristic properties.

Science and Technology - Content Standard E

Science and technology are reciprocal. Science helps drive technology and technology is essential to science.

History and Nature of Science - Content Standard G

Scientists formulate and test their explanations of nature using observation, experiments, and models.

From the National Science Education Standards (1996) and the Framework for K-12 Science Education (2012) National Academies Press.

P

P

P

P

How does a water softener work? Look up water softeners on the internet and write a description of how they work. Discuss how technology has helped us purify water.

Technology KOG— Chapter 3

Discuss how balance, proportion and contrast combine with the elements of the visual arts.

Art KOG—Chapter 3

Have your student critically evaluate all they have learned this week. How does all of this information contribute to our understanding of chemical reactions?

Critical Thinking KOG— Chapter 3

Layout design: Karen Wood and Derrick WoodOriginal Content: Karen WoodGraphic design: David Keller

Copyright © 2013 Gravitas Publications, Inc.All rights reserved.

No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. No part of this booklet may be used or reproduced in any manner whatsoever without written permission.

Focus On Middle School Chemistry Study Folder and Answer KeyISBN # 978-1-936114-80-1


Special thanks to Marjie Bassler for copy editing and review of the manuscript. Also, a special thank you to all of the parents and students from Intelligent By Design Science Enrichment Education classes for their critical evaluation of the text. Finally, special thanks to Dr. Rebecca W. Keller for her encouragement to go forward with this project.

TABLE OF CONTENTSFocus On Middle School Chemistry Study Folder

Directions i

OptionalStudyFolderCover ii

Chapter1 Matter 1

Chapter2 Molecules 2

Chapter3 ChemicalReactions 3 NoteFlappers3.5and3.7 3a

Chapter4 Acids,Bases,andpH 4 NoteFlapper4.3 4a

Chapter5 Acid-BaseNeutralization 5 NoteFlapper5.3A 5a

Chapter6 Mixtures 6 NoteFlapper6.3 6a

Chapter7 SeparatingMixtures 7 NoteFlapper7.5A 7a

Chapter8 EnergyMolecules 8 NoteFlappers8.4Band8.5 8aChapter9 Polymers 9

Chapter10 BiologicalPolymers:Proteins—PartA 10 NoteFlapper10.5A 10a

BiologicalPolymers:DNA—PartB 10b NoteFlappers10.7Band10.7C 10c

This study folder is an aid to help you memorize key words/terminologies and

definitions. To use this guide simply write the missing word(s) in the empty

spaces within each sentence. Some definitions require more description

which may need to be in the form of a sentence defining the word(s). Some

sections of the chapter ask you to draw pictures and label them. You will need

two manila file folders to make your Study Folder. To assemble the Study

Folder, begin by cutting out each Chapter Page section along the line labeled

then glue that cut out page onto one of the sections of your

manila folder. Use the front and back of the tri-fold folder. Some pages have

Note Flappers and some have Book Flappers associated with them, and these

flappers will be cut out individually. Simply match the TAB number or

LABEL on the Note/Book Flapper with the TAB number or LABEL on the

chapter page. There are some Note Flappers that STACK on top of each other

in some chapters, and these will be labeled as such. This kit contains the

Student Note Pages and a Teacher’s Answer Key. Chapters 1-5 will be glued

onto one folder and Chapters 6-10 onto the second folder. Each tri-fold folder

will provide FIVE sections to glue the Chapter Pages onto. A narrower Study

Folder cover sheet is included and can be used by the student as the cover for

either of the two folders. The cover can be cut out and glued to the front

section of either folder.

Remember this is YOUR personal Study Folder.

Make as many notes in it as you like. Have fun learning!

CUT HERE

Open your manila folder flat.

Now make two NEW folds about 1/3 away from the center fold.

cen

ter

cen

ter

fold here 1/3 from center

original center fold

Glue one cut out Student Chapter Note section to one of the FIVE folded sections. Use both sides of the folder.

We recommend gluing one Student Chapter Note section at a time as it is being discussed.

i

CHAPTER #: CHAPTER 3: CHEMICAL REACTIONS

Description of a

occurs when a ______________ decomposes or _____________ apart, into ____ or more _____________.

occurs when ____ or more molecules ___________________ with each other to make a new _________________________

GL

UE

T

AB

3.7

HE

RE

CU

T H

ER

E

CU

T H

ER

E

Fill in the blanks and write the symbol for each atom on the circles

High ______________ or ______________current

Also known as

(

)

Name Symbol Atomic Number

PT

Write the name, symbol and atomic

number of each on the lines below.

3.1

3.2

3.3

3.6

3

Name ________________________ Date ________________

Focus On Middle School Chemistry, Chapter 1Quiz for Chapter 1, Middle School Chemistry (20 questions, 10 points each, 200 points total)

1. Who is credited for creating the first periodic table? (10 points)

Dmitri Mendeleev

John Dalton

Albert Einstein

George Washington

2. Uranium is the heaviest naturally occurring element. (10 points)

True

False

3. The symbol for lithium is Li. (10 points)

True

False

4. The word "atom" means... (10 points)

Electron

Smallest particle

Uncuttable

Matter

5. The symbol for hydrogen is... (10 points)

Hg

H

Hy

He

6. The atomic weight is the sum of the protons and neutrons. (10 points)

True

False

7. Match the following elements with their symbols (you may use a periodic table). (10 points)

_____ Aluminum

_____ Sodium

_____ Fluorine

_____ Hydrogen

a. Na

b. Al

c. H

d. F

8. What is the lightest element? (10 points)

Helium

Lithium

Hydrogen

Uranium

9. All of the elements in the right hand column of the periodic table are called the alkali metals.(10 points)

True

False

10. The number of protons for uranium is 92. (10 points)

True

False

11. Beryllium is an alkaline earth. (10 points)

True

False

12. Vertically, the elements are arranged according to their chemical properties. (10 points)

True

False

13. In an atom, the number of protons equals the number of electrons. (10 points)

True

False

14. What are the first 10 elements in the periodic table going from smallest to largest?(10 points)

_____ Oxygen

_____ Boron

_____ Fluorine

_____ Nitrogen

_____ Carbon

_____ Helium

_____ Beryllium

_____ Hydrogen

_____ Lithium

_____ Neon

15. Fluorine is a noble gas. (10 points)

True

False

16. How many electrons does lithium have? (10 points)

0

9

3

6

17. Match the description to the proper element. (10 points)

_____ Sodium

_____ Helium

_____ Calcium

_____ Fluorine

a. Alkali metal

b. Noble gas

c. Alkaline earth

d. Halogen

18. Match the following atomic weights to the proper element (you may use a periodic table).(10 points)

_____ Helium

_____ Hydrogen

a. 12.0

b. 1.0

c. 14.0

d. 4.0

_____ Nitrogen

_____ Oxygen

_____ Carbon

e. 16.0

19. What forms the nucleus, or core, of the atom? (Check all that apply.) (10 points)

Orbitals

Matter

Neutrons

Electrons

Protons

20. Atoms are composed of which three types of smaller particles? (Check all that apply.)(10 points)

Neutrons

Matter

Electrons

Magnitrons

Protons

Nucleic Acids

Answer Sheet


Dmitri Mendeleev1.

True2.

True3.

Uncuttable4.

H5.

True6.

b, a, d, c7.

Hydrogen8.

False9.

True10.

True11.

True12.

True13.

8, 5, 9, 7, 6, 2, 4, 1, 3, 1014.

False15.

316.

a, b, c, d17.

d, b, c, e, a18.

Neutrons, Protons19.

Neutrons, Electrons, Protons20.

Name ________________________ Date ________________


1. What type of reaction happens between sodium and chlorine to produce sodium chloride(table salt)? (10 points)

Exchange reaction

Combination reaction

Decomposition reaction

Displacement reaction

2. When a reaction occurs, which of the following can happen to the solution? (Check all thatapply.) (10 points)

It might get colder.

It might get hotter.

It might release bubbles.

It might form a precipitate.

3. What is the breakup of water molecules into hydrogen gas and oxygen gas molecules?(10 points)

Exchange reaction




4. A precipitation can look like sand, mud, dust, or snow forming. (10 points)True

False

5. What is the formation of sodium hydroxide by two water molecules and two metallic sodiumatoms an example of? (10 points)


Exchange reaction



6. A spontaneous reaction means it happens all by itself. (10 points)

True

False

7. A chemical reaction occurs whenever bonds between atoms and molecules are created ordestroyed. (10 points)

True

False

8. The decomposition reaction of water into hydrogen gas and oxygen gas is a spontaneousreaction. (10 points)

True

False

9. When sodium metal combines with chlorine gas, the combination reaction produces what?(10 points)

Hydrogen gas and water

Sodium hydroxide and hydrochloric acid

Sodium chloride (table salt)

Sodium chloride (table salt) and water

10. In a displacement reaction, one atom kicks another atom out of a molecule. (10 points)True

False

11. In an exchange reaction, one atom trades places with another atom. (10 points)True

False

12. In a decomposition reaction, two or more molecules combine to make a new molecule.(10 points)

True

False

13. When a reaction occurs, you might observe what type of change? (Check all that apply.)(10 points)

Bubbles forming

Precipitation

Color change

Temperature change

14. When two water molecules break apart, the decomposition reaction produces what?(10 points)

Hydrogen gas and oxygen gas

Sodium chloride and water

Sodium chloride

Sodium hydroxide and hydrochloric acid

15. When a temperature change occurs, a solution only gets hotter. (10 points)True

False

16. The reaction between hydrochloric acid and sodium hydroxide is a spontaneous reaction.(10 points)

True

False

17. Match the result to the proper type of reaction. (10 points)

_____ Displacementreaction

_____ Combinationreaction

_____ Exchange reaction

_____ Decompositionreaction

a. occurs when one atom trades places with another atom

b. occurs when a molecule decomposes, or breaks apart,into two or more molecules

c. occurs when one atom kicks another atom out of amolecule

d. occurs when two or more molecules combine with eachother to make a new molecule

18. When hydrogen chloride and sodium hydroxide react, the exchange reaction produces what?(10 points)

Sodium chloride (table salt) and water

Sodium hydroxide and hydrogen gas

Hydrogen gas and oxygen gas

Sodium chloride (table salt)

19. In a combination reaction, one atom kicks another atom out of a molecule. (10 points)True

False

Answer Sheet


1. Combination reaction

It might get colder., It might get hotter., It might release bubbles., It might form a

precipitate.

2.

Decomposition reaction3.

True4.

Displacement reaction5.

True6.

True7.

False8.

Sodium chloride (table salt)9.

True10.

True11.

False12.

Bubbles forming, Precipitation, Color change, Temperature change13.

Hydrogen gas and oxygen gas14.

False15.

True16.

c, d, a, b17.

Sodium chloride (table salt) and water18.

False19.

Exchange reaction20.

20. The reaction of hydrochloric acid and sodium hydroxide is an example of which type ofreaction? (10 points)

Exchange reaction




Name ________________________ Date ________________

Focus On Middle School Chemistry Midterm 1, Chapters 1-5Midterm quiz for Chapters 1-5, Middle School Chemistry (20 questions, 10 points each, 200 points total)Sample questions Chapters 1 & 3

1. In an atom, the number of protons equals the number of electrons. (10 points)True

False

2. What forms the nucleus, or core, of the atom? (Check all that apply.) (10 points)

Electrons

Orbitals

Neutrons

Matter

Protons

3. Match the following atomic weights to the proper element (you may use a Periodic Table).(10 points)

_____ Nitrogen

_____ Carbon

_____ Oxygen

_____ Helium

_____ Hydrogen

a. 14.0

b. 16.0

c. 1.0

d. 12.0

e. 4.0

4. Match the following description to the proper element. (10 points)

_____ Calcium

_____ Fluorine

_____ Helium

_____ Sodium

a. Alkali metal

b. Halogen

c. Alkaline earth

d. Noble gas

9. Match the result to the proper type of reaction. (10 points)

_____ Combinationreaction

_____ Decompositionreaction

_____ Displacementreaction

_____ Exchange reaction

a. occurs when one atom trades places with another atom

b. occurs when one atom kicks another atom out of amolecule

c. occurs when two or more molecules combine with eachother to make a new molecule

d. reaction occurs when a molecule decomposes, or breaksapart, into two or more molecules

10. When a reaction occurs, you might observe what type of change? (Check all that apply.)(10 points)

Temperature change

Color change

Bubbles forming

Precipitation

11. A chemical reaction occurs whenever bonds between atoms and molecules are created ordestroyed. (10 points)

True

False

12. The decomposition reaction of water into hydrogen gas and oxygen gas is a spontaneousreaction. (10 points)

True

False

Answer Sheet

Focus On Middle School Chemistry Midterm 1, Chapters 1-5Midterm quiz for Chapters 1-5, Middle School Chemistry (20 questions, 10 points each, 200 points total)Sample questions Chapters 1 & 3

True1.

Neutrons, Protons2.

a, d, b, e, c3.

c, b, d, a4.

c, d, b, a9.

Temperature change, Color change, Bubbles forming, Precipitation10.

True11.

False12.

GRAPHICS

Illustrations: Janet Moneymaker


All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. No part of this book may be used or reproduced in any manner whatsoever without written permission.

Focus On Middle School Chemistry Graphics Package

Published by Gravitas Publications Inc.Real Science-4-Kids®www.realscience4kids.comwww.gravitaspublications.com

Focus On Middle School Chemistry


All of the elements in a single column have similar properties.

Increasing atomic number



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