Chemistry!

What does this have to do with Biology????

Bell Ringer: Use the graph below to answer the following questions

a. Which 4 elements are the most common in the human body?

b. Which 2 elements compose a little over 25% of the body?

c. Why do you think there is a lot of oxygen and hydrogen in the human body?

Carbon (C), Hydrogen (H), Oxygen (O), & Nitrogen (N)

make up over 96% of the mass of a human body!!!

PIE CHART

Objective/Topic

Objective:

• SWBAT: Describe the structure of an atom in an atom building activity.

Topic:

• Atoms and Elements

Why Study Chemistry?

• Chemistry is the study of matter, its composition, and properties.

• Matter is anything that has mass and takes up space.

Atoms:

• Definition: building blocks of matter• Made up of three subatomic particles:

1. Protons (positively charged)2. Neutrons (no charge)3. Electrons (negatively charged)

Structure of An Atom

• Neutrons and Protons are located at the center of the atom which is called the nucleus.

• Electrons are located in energy levels that circle the nucleus.

• Atoms contain an equal number of protons and electrons, so the overall charge is 0

Structure of An Atom

Electron energy levels(Electrons)

Nucleus(Protons and Neutrons)

Label Your Atom!

Electron Energy Levels

1st 2 e-2nd 8 e-3rd 18 e-

# electrons = # protons; Net Charge = 0

Electron Energy Levels

SUBATOMIC PARTICLE

CHARGE LOCATION IN THE ATOM

PROTON POSITIVE In the NUCLEUS

NEUTRON No CHARGE In the NUCLEUS

ELECTRON NEGATIVE In the energy levels

Elements

• Definition: Pure substance that cannot be broken down into other substances.

• Made up of ONE type of atom.• Example: Carbon, Hydrogen, Oxygen

Hydrogen

1

H1.008

The Periodic Table: A Key to the Elements

Element

Atomic #

Symbol

Atomic Mass

State of Matter

P

P + N

Atomic Number and Atomic Mass

Atomic number:

Atomic Mass:

the number of protons in the nucleus

the total number of particles in the nucleus

(protons + neutrons)

Atomic Structure LabReview!

Protons: positive charge (p+)Neutrons: no charge/neutral (n0)Electrons: negative charge (e-)

Energy Levels:1st 2 e-2nd 8 e-3rd 18 e-

Net Charge of an Atom: = ZERO p+ and e- cancel each other

ATOMIC STRUCTURE LAB!

Red = PROTONS (p+)

White = NEUTRONS (n0)

Green = ELECTRONS (e-)

Expectations (How to get an A)

• Work with 1 partner• 18 beans• DO NOT drop, throw, or lose them.• Your grade depends on your responsibility

with the beans.

Atomic Structure LabFinish!

Lay out beans on diagram

Draw pictures

Answer questions

Homework:

• Vocabulary Foldable:1. Chemistry2. Atom3. Elements4. Atomic Mass5. Atomic Number

Bell Ringer Look at the graph below and answer the following questions

a. Which element has the highest percent in living things?

b. What is the label on the y-axis?

c. Which elements are most abundant on the earth?

Objective/Topic

Objective:• SWBAT: Compare and

contrast ionic and covalent bonds in a Venn Diagram.

Topic:• Chemical Bonds

Demonstration

• Glucose is a simple sugar that provides energy for cells.

• In this demonstration, I will use a reagent called Benedict’s Solution, which indicates the presence of glucose and other simple sugars in food.

• A color change determines whether or not these foods have sugar.

Glucose Molecule

Directions:

• Use the table on your notes to fill in the data as we go.

• Take one minute, and predict for each item whether or not they have sugar (glucose)

Analysis Questions:

• Did any of the foods contain simple sugars? How do you know?

• Could a food labeled “Sugar-Free” test positive using Benedict’s solution as an indicator. Explain why or why not.

Sulfur 16

S 32.06

Use the information about Sulfur from the periodic table to answer the following questions:

a. What is the atomic number?

b. What is the Chemical Symbol

c. How many electrons does Sulfur have?

d. What is the atomic mass?

e. How many neutrons does Sulfur have?

16

S

16

32.0616

16

P + N = Atomic Mass

REVIEW!!!

Think, Pair, Share

• Describe how you think the sugars in food “Stick” together. How do you think they are broken apart?

BONDING!!!!!!When we digest food, we break the

bonds and release the energy we need.

A compound is a substance that is composed of atoms of two or more different elements that are chemically combined.

Example:

Table salt is NaCl (Sodium + Chlorine)

Compounds and Bonding

StabilityStable atoms’ outer energy levels are

filled with electronsEx: 8 electrons in the 2nd energy

level

A stable atom is happy An unstable atom is unhappy

Covalent Bonds

Elements can SHARE electrons to fill their energy shells to become more stable

Covalent bond: the force that holds 2 atoms together by sharing electrons

Sugars, fats, proteins and water are all held together by covalent bonds!

• Two hydrogen atoms

can combine with each other by sharing their electrons.

• Each atom becomes stable by sharing its electron with the other atom.

Hydrogen molecule

HOW DO COVALENT BONDS FORM?

Covalent Bonding (Water - H20)

Ionic BondsAtoms usually have equal numbers of positive

protons and negative electrons so they are neutral (charge =

Sometimes an atom gains or loses an electron in it’s outer shell, becoming charged (+ or -)

0)

Attractive force between two ions of opposite charge Ex: Na loses an e- to Cl to form NaCl

IONIC BONDS

Ions Charged particles made of atoms

Ionic bond

TimMoby

In Your Notes!

• Draw a Venn Diagram that Compares and Contrasts Ionic Bonds and Covalent Bonds.

Homework:

• Vocabulary Foldable with the terms:1. Compound2. Covalent Bond3. Ion4. Ionic Bond5. Molecule

Bell Ringer/Objective

Bell Ringer:• Compare and Contrast ionic

and covalent bonds (draw a Venn Diagram)

Objective:• SWBAT: Describe the

importance of enzymes in chemical reactions in a demonstration.

Demonstration

• When sliced, an apple’s soft tissue is exposed to oxygen, causing a chemical reaction called oxidation. Enzymes in the apple speed this reaction, producing darkened, discolored fruit.

• In this demo, we will investigate methods used to slow this enzymatic browning.

Directions:

• Make your predictions on your data table.

• We will fill in the data table after lecture.

Chemical Reactions

• When you lie down for the night, you might think that your body is completely at rest. In fact, you are still digesting the food that you ate that day, the scrape on your elbow is healing, and your muscles and bones are growing and developing. All the things that happen inside your body are the result of chemical reactions!

Chemical Reactions

• A chemical reaction is the process by which atoms or groups of atoms in substances are reorganized into different substances.

Example:

• The rust on the car is a compound called iron oxide (Fe2O3), and it was formed when oxygen (O) in the air interacted with the iron (Fe) in the car.

Chemical Equations:

• Reactant: the starting substances on the left side of the chemical equation.

• Products: the ending substances on the right side of the chemical equation.

Ex.

Check For Understanding

• Which of the following is a chemical reaction?a. tearing paper into stripsb. burning paperc. picking up iron filings with a magnet

Activation Energy

• Activation energy is the minimum amount of energy needed for reactants to form products in a chemical reaction.

Ex.A candle will not burn until you light its wick.Food needs to be cooked in order for the ingredients to come together.

Enzymes

• Catalyst- a substance that lowers the activation energy needed to start a chemical reaction.

• Enzymes- special proteins that are biological catalysts that speed up the rate of chemical reactions in biological processes.

Ex. Amylase (enzyme found in saliva to speed up digestion)

Check For Understanding

The various enzymes in our bodies are _____.a. lipidsb. carbohydratesc. proteins

Demo:

• Look at the apple slices and fill in your data table.

1. Analyze how each treatment affected the chemical reaction that occurred on the apple. What made it successful?

2. If a restaurant owner wanted to serve fresh-cut fruit, which preparation method might he choose?

Homework:

• Finish analysis questions from the demonstration.

CATALYST

1.Write down all the uses for water you can think of.

2. What are the three states of matter? Which state is water in?

Objective/Topic

Objective:• SWBAT: Summarize the

three properties of water in teacher-led demonstrations.

Topic:• Water/PH scale

OIL AND WATER• 1. HYPOTHESIS- What will happen when oil

and water mix?

OIL AND WATER• 2. RESULTS- What did happen when water

and oil mixed?

HYPOTHESIS-

What do you think will happen to the balloon filled with air when it is placed over the flame?

HYPOTHESIS-

What do you think will happen to the balloon filled with water when it is placed over the flame?

DROPS ON A PENNY• 1. HYPOTHESIS- How many drops of water

can be placed on a penny before it spills over?

RECALL…• What is the chemical symbol for water?H2O

• What is water made of?

Hydrogen and Oxygen

How is the compound H20 formed?Hydrogen gas reacting with oxygen

Shared electrons

Hydrogen Hydrogen

Oxygen

Water & Its Importance

• Water is perhaps the most important compound in living organisms.

• Water makes up 70% – 95% of most organisms.

Take Notes!

Why is water so important?

Water makes up 70% – 95% of most organisms

Topic: Properties of Water

Water Is Polar• Sometimes, when

atoms form covalent bonds, they do not share the electrons equally. This is called a polar bond.

• A polar molecule is a molecule with an unequal distribution of charge; that is, each molecule has a positive end and a negative end. – Ex: water

Sugar Molecules Dissolving

Water can dissolve many ionic compounds, such as salt, and many other polar molecules, such as sugar.

Water has surface tension

• Water molecules also attract each other (hydrogen bonding)

Floating on water Capillary action

Fresh morning dew on a Water Horsetail

Surface tension prevents a coin from sinking: the coin is denser than water, so it cannot be floating due to buoyancy alone.

Water Resists Temperature Changes

Water resists changes in temperature. Therefore, water requires more heat to increase its temperature than do most other common liquids.

Why does ice float?

Why do roads crack in places with cold winters?

Water Expands When It FreezesIce is less dense than liquid water so it floats as it forms in a body of water.

Take Notes!

1. Water is polar (has a + and - end)

2. Water resists temperature changes

3. Water expands when it freezes

Topic: Properties of Water

Unique properties of water

How do living things use water?

- Maintaining temperature- Transportation in the body- Dissolving things (ex: sugars)- Digesting food, breathing, and lubricating joints

• HYDROPHOBIC- water hating, when water (polar) is combined with a non polar substance

Example- drops of water on a leafOR oil in water

• HYDROPHILIC – water loving, when water (polar) is combined with a polar substance

Example – magic snow

Water!

TimMoby

1. Water is made from 2 different elements: positively charged _____________ and negatively charged _____________.

2. Water’s ___________ is what makes the molecules clump together into round drops and also causes the skin, or _________________ that forms on the surface of water.

3. Water is known as the ______________ solvent, which means it is good at dissolving just about anything.

4. The salt dissolved in sea water _________ the oceans freezing point.

5. Water is the main ingredient of our ________, fills our cells, and makes up about ____% of our body weight.

6. Water covers over ____% of our Earth’s surface

Surface tension

Oxygenstickiness

universal

lowers

blood

Hydrogen

65

70

pH• pH is how acidic or basic a solution is

• A scale with values from 0-14 is used to measure pH

Strong Acid Weak BaseWeak Acid Neutral Strong Base

ACIDS

• pH below 7, sour or bitter taste, forms H+ ions in water

BASES• pH above 7, forms OH- ions in water

NEUTRAL

• pH of 7, not an acid or base