Unit 2

Question 1

The building blocks of matter are ___________.

Answer 1

Atoms

Question 2

What are the 3 subatomic particles and where are they located?
Also, what are the charges?

Answer 2

1) protons- in the nucleus (+)
2) neutrons- in the nucleus (no charge)
3) electrons- in the electron cloud outside the nucleus (-)

Question 3

What are some uses for chlorine and fluorine

Answer 3

• both halogens are in water

- go in water to kill bacteria

Question 4

Define strong nuclear force

Answer 4

Holds atoms together

Question 5

The atomic number of an element is the same as the _______________. The number of neutrons + the number of protons tells us the _______.

Answer 5

Amount of protons

Mass

Question 6

Define isotope & how many protons, neutrons and electrons are in a Hydrogen-3 (tritium) isotope?

Answer 6

Isotope- an average of all known types of an element
Protons- 1
Neutrons- 2
Electrons-1

Question 7

What are valence electrons and how can you find out how many valence electrons an element has? Name the diagram used to show the valence electrons of an element.

Answer 7

Valence electrons are the electrons that are in the outer shell
You can find out how many valence electrons an element has by looking at the last number of the group. The diagram that is used to show valence electrons is a Lewis dot diagram.

Question 8

Where are the number of each atom shown on chemical formula?

Answer 8

Subscripts

Question 9

What is an oxidation number?

Answer 9

An oxidation number shows the charge, and how many atoms they need in their outer shell.

Question 10

What is the octet rule?

Answer 10

If it has 8 electrons in its outer shell, it’s stable

Question 11

Calcium has an atomic number of 20. How many filled energy levels does it have and how many are left over?

Answer 11

It has 3 filled energy levels and it has 2 left over.

First energy level has 2, the rest have 8, which puts us at 18 and you will have 2 in the outer shell

Question 12

Why are Noble Gases considered non-reactive?

Answer 12

They have a full valence shell of 8 valence electrons.

Question 13

What do scientists call the place where electrons are found?

Answer 13

The electron cloud

Question 14

What are the benefits of the following elements:
Chlorine:
fluorine:

Answer 14

Cl: used in pools and kills bacteria
F: used in water too, but more in toothpaste

Question 15

What are the only two elements that are liquid at room temperature?

Answer 15

Bromine and Mercury

Question 16

Identify where on the periodic table these families are found, their valence electrons sand their oxidation numbers.
Halogens, alkali metals, alkaline earth metals and noble gases

Answer 16

Halogens: oxidation number- 1- group 17 7 Val e-
Alkali metals: group 1; 1 Val e-, oxidation # - 1+
Alkaline earth metals: group 2, oxid. 2-, 2 Val e-
Noble gases: group 18, 8 Val e-, oxidation # 0

Question 17

As you move from left -> right across the periodic table, what happens to the mass and size of the element?

Answer 17

They increase

Question 18

The ____ __ of an element is the total number of protons and neutrons in the nucleus.

Answer 18

Mass #

Question 19

Elements with similar properties are listed in a single column on the periodic table called _______.

Answer 19

groups

Question 20

What are some of the characteristics of alkali metals? Alkaline earth metals?

Answer 20

Alkali: shiny, group 1, oxid. # 1+

Alk. earth metals: group 2, oxid # 2+

Question 21

Be able to explain Ernest Rutherford’s experiment and the discoveries from it.

Answer 21

He did the gold foil experiment and discovered that atoms are made up of mostly empty space.

Question 22

Where are non-metals located on the periodic table? _________ Metals? _____

Answer 22

Right of staircase

Left of staircase

Question 23

Ionic bonds form between

Answer 23

Metals & non-metals

Question 24

Covalent bonds form between

Answer 24

Two non-metals

Question 25

In the formation of an ionic bond, the metal _____ electrons and the non-metal ______ electrons

Answer 25

loses

Gains

Question 26

What is so unique about carbon

Answer 26

It can be used for fossil dating (carbon-14 , and/or anything that was living for that matter) and radiometric dating

Question 27

How do you figure out how many valence electrons an atom will have by looking at the periodic table?

Answer 27

You look at the last number of a group

Question 28

What does the oxidation number tell us about an element? How do you find out an elements oxidation number by looking at the periodic table?

Answer 28

How many electrons an element is willing to give up/gain

By looking at the column number

Question 29

How many valence electrons does an atom need to be considered stable?

Answer 29

8

Question 30

What are the only two elements that don’t follow this rule? How many valence electrons do they need?

Answer 30

Hydrogen and Helium

2

Question 31

How many atoms of each element are in 4H O?

2

Answer 31

H: 8
O: 4