Chemistry 1 Test Review

• The periodic table is organized by– Atomic number – increasing from left to right– Columns called groups or families – element

have similar properties and the same number or valance electrons

– Rows called periods - periods increase down the period table. The period number is equal to the number of energy levels (shells) in an element

• The organization of the periodic table allows easy use and provide a lot of information in one page.

1) How is the organization of the Periodic Table beneficial (What does it tell you? What are the patterns?)

Metalsmetalloids

Nonmetals

2) On the periodic table below, identify the area where the metals, non-metals & metalloids are located:

2 – Continued!

• Metals – ductile (can be pulled into a wire)– Malleable (can be pounded into a sheet)– Shiny– conductors

• Non Metals– brittle– dull– insulators

• The most reactive side of the periodic table is the left side. The reactivity decreases to the right

Most reactive Least reactive

3) Which side of the periodic table contains the most reactive elements? Least reactive?

3 continued

• Sodium is very reactive. That means it easily combines with other elements to form a compound

• Neon is not reactive. It does NOT combine with other atoms.

• The elements in the same group have similar properties

• See next slide for examples

4) When looking at a Periodic Table, how do you know which elementshave similar properties? Give an example.

Alkali metals Group 1

Soft and shiny and reacts violently with water.

Positive 1 ion

Alkaline-earth metals

Group 2

Reactive metal with two valance electronsPositive 2 ion

HalogensGroup 17

Noble gasesGroup 18

Noble gases exist in the form of gas because they don't react with other elements. Do not bond to form compounds.

4 - continued

For each sub-atomic particle, describe its charge, its contribution to the mass of the atom and where it is found in an atom. In addition, describe the charge of an atom with the same number of protons and electrons.

5)

• Protons– positive– Has (adds) mass– Found in the nucleus

• Neutrons– nuetral– Has (adds) mass– Found in the nucleus

• Electrons– negative– Has virtually no mass– Found in the “electron cloud”

• An atom with an equal number of protons and electrons is neutral; the equal number of charges balances out.

• An atom with an unequal number of protons and electrons is charge.– Negatively charged if it has more electrons– Positively charged if it has more protons

5 – Continued!

Element Symbol # of Proton

s

# of Electron

s

# of Neutron

s

Atomic Numbe

r

Atomic Mass

ValenceNumber

Oxygen O 8 8 8 8 15.999 (16)

6

Silicon Si 14 14 14 14 28.086 (28)

4

Iron Fe 26 26 30 26 55.845 (56)

Variable

Aluminum Al 13 13 14 13 26.982 (27)

3

Calcium Ca 20 20 20 20 40.078 (40)

2

Fill in the following chart:6)

7)For the element Oxygen:

A - 8P - 8E - 8

M - 16A - 8N - 8

A. How many protons?

8B. How many neutrons?

8C. How many electrons?

8D. Bohr Model

p = 8n = 8

7-continued)For the element Silicon:

A - 14P - 14E - 14

M - 28A - 14N - 14

A. How many protons?

14B. How many neutrons?

14C. How many electrons?

14D. Bohr Model

p = 14n = 14

7-continued)For the element Aluminum:

A - 13P - 13E - 13

M - 27A - 13N - 14

A. How many protons?

13B. How many neutrons?

14C. How many electrons?

12D. Lewis Dot Diagram

Al

7-continued)For the element Calcium:

A - 20P - 20E - 20

M - 40A - 20N - 20

A. How many protons?

20B. How many neutrons?

20C. How many electrons?

20D. Lewis Dot Diagram

Ca

8) What do periods tell us about an element? What is the pattern on the Periodic Table (top to bottom)?

The Period is the number of energy levels (rings) that elements in that row has. The period increases from top to bottom of the Periodic Table.

1234567incr

easi

ng

9) What do groups tell us about an element? What is the pattern?

The Group (also known as family) includes related elements that all have the same number of electrons in their outer energy level.

1 2 3 4 5 6 7 8

increasing

10) What can we say about the number of protons as we move from left to right across the Periodic Table.

The number of protons (and of course the atomic number) increases from left to right AND from top to bottom on the Periodic Table

increasing

11) Where can the protons, electrons and neutrons be found in an atom (be specific)?

ProtonsNeutrons

electrons – “energy levels” (orbits)

nucleus

protonsneutrons

electrons

12) How do you calculate the mass of an atom?

Mass of the atom is the number of protons plus number of neutrons.

HINT: it is the “MAN” in APE MAN

Mass = number + neutrons

(remember that number is protons!)

13) What are common properties of metals, nonmetals and metalloids?

Metals: good conductorsshinymalleable: can be pounded into thin

sheets; think aluminum foilductile: can be pulled into wires

Metalloids: some properties of both metals and nonmetals.

Non-Metals: NOT good conductors, NOT shiny, NOT malleable, not ductile

End Test Review Answers….

Old slides follow.

14) What is an ion? If you have a sodium ion, what is its electrical charge?

An ion is an atom that has gained or lost an Electron. ELEMENTS DO NOT GAIN ORLOSE PROTONS. Since electrons are negative, when you lose one, the atom becomes positive.

Since sodium has 1 lonely electron on its outter shell, it will lose that electron and become positive by one: Na+1.

15) What is an isotope?

An isotope is an atom that has one more or one less neutron. Since protons and neutrons make up the mass of the atom, isotopes have different weights.

The reason that the mass of atoms on the periodic table is a “decimal” is because it is the weighted average of different isotopes of that element.

NOTE: ATOMS NEVER GAIN/LOSE PROTONS!

Old question….)What is the difference between and element and a compound?

Elements are the smallest “piece” of material and have common properties.Compounds are substances that are made up of atoms.

For example, hydrogen and oxygen are elements. They combine to form water H2O

7-A) For the element Hydrogen:

A - 1P - 1E - 1

M - 1A - 1N - 0

A. How many protons?

1B. How many neutrons?

0C. How many electrons?

1D. Bohr Model

E. Lewis Dot

p = 1n = 0

H

7-B) For the element Lithium:

A - 3P - 3E - 3

M - 7A - 3N - 4

A. How many protons?

3B. How many neutrons?

4C. How many electrons?

3D. Bohr Model

E. Lewis Dot

p = 3n = 4

Li

7-C) For the element Sodium:

A - 11P - 11E - 11

M - 23A - 11N - 12

A. How many protons?

11B. How many neutrons?

12C. How many electrons?

11D. Bohr Model

E. Lewis Dot

Na

p = 11n = 12