Unit 2: Chemistry (Topics 1-2)

Question 1

What is Chemistry?

Answer 1

Chemistry is the study of matter and the changes matter undergoes.

Question 2

What is matter?

Answer 2

-Matter is anything that has mass and occupies space
-It is everything that makes up the world around us

Question 3

What are the five main points of the Particle Model of Matter?

Answer 3

-All matter is made up of extremely tiny particles
-Each pure substance has its own kind of particle, different from the particles of other pure substances
-Particles are always moving
-Particles attract each other
-Particles at a higher temperature move faster than particles at a lower temperature

Question 4

What are the three states of matter?

Answer 4

-Gas
-Liquid
-Solid

Question 5

Describe the three states of matter.

Answer 5

Gases - weak forces, particles freely moving.
Liquids - stronger forces, particles held together, but still spread out.
Solids - strongest forces, particles hold in a definite shape.

Question 6

What is a pure substance?

Answer 6

Pure substances have unique particles, only one type of particle.

Question 7

What are the two types of pure substances.

Answer 7

-Elements
-Compounds

Question 8

Describe each type of pure substance.

Answer 8

Elements have one type of atom, compounds have more than one types of atoms.

Question 9

What are mechanical mixtures and what type of mixture are they?

Answer 9

Mechanical mixtures are mixtures where you can easily see the different parts. They are a type of heterogeneous mixture.

Question 10

What are the two types of changes that matter undergoes?

Answer 10

1. Physical Change
2. Chemical Change

Question 11

What is physical change and what is an example?

Answer 11

Physical change is when the substance changes in form only, the chemical composition stays the same. An example of this is water. When water boils, freezes, or condenses, it is still just water.

Question 12

What is chemical change and what is an example?

Answer 12

Chemical change is when one or more new substances are formed. Chemical change includes all chemical reactions. An example of this is when we digest our food.

Question 13

What are the two types of properties of matter?

Answer 13

1. Physical Properties
2. Chemical Properties

Question 14

What are physical properties?

Answer 14

These are properties you can see or measure, without forming a new substance.

Question 15

What are the two categories of physical properties and briefly describe each.

Answer 15

1. Qualitative - can be described but not measured (Ex. colour, taste, smell).
2. Quantitative (“Quantity”) - can be measured (Ex. melting temperature, density, conductivity, solubility).

Question 16

What is a chemical property?

Answer 16

A property that describes how a substance behaves in a reaction. They react with water, air, acids, and are combustible.

Question 17

What does WHMIS stand for?

Answer 17

Workplace Hazardous Material Information System

Question 18

What are pieces of evidence that tells you when a chemical change is taking place?

Answer 18

-Change in colour
-Change in odor
-New substance is formed

Question 19

What is the law of definite proportion?

Answer 19

A chemical compound will always have the same proportions or amount of each element, no matter what the amount is, or source.

Question 20

What are Atoms?

Answer 20

The smallest particle of an element that cannot be broken down chemically.

Question 21

What are the four points of Dalton’s Atomic Theory?

Answer 21

-All matter is made up of atoms
-Atoms cannot be created, destroyed, or broken down
-All atoms of one element are identical in mass and size and are different from other elements
-Compounds are created when elements combine in definite proportions

Question 22

What is Electrolysis and what did it lead to?

Answer 22

The process of decomposing a chemical compound by passing an electrical current through it. Led to the isolation of elements such as sodium, calcium, magnesium, strontium, and barium.

Question 23

What is the Law of Conservation of Mass?

Answer 23

In a chemical change, the total mass of the new substances is always the same as the total mass of the original substances.

Question 24

Who first developed the Periodic Table of the Elements and how?

Answer 24

Dmitri Mendeleev. He organized the elements in order of their atomic masses.

Question 25

What is atomic mass?

Answer 25

The average mass of an atom of an element.

Question 26

What are elements?

Answer 26

-Pure substances
-Cannot be broken down any further than they already are

Question 27

What common properties do metals have?

Answer 27

-Solid at room temperature (except for mercury Hg)
-Shiny appearance
-Conducts electricity and heat
-Able to be hammered flat
-Can be drawn out into a wire

Question 28

What common properties do nonmetals have?

Answer 28

-Gas or solid at room temperature (except for bromine which is a liquid)
-Not shiny
-Brittle
-Can’t be drawn out into a wire
-Don’t conduct heat or electricity

Question 29

What common properties do metalloids have?

Answer 29

-Solids at room temperature
-Some are lustrous some are dull
-Some are conductors of electricity
-Not heat conductors
-Not ductile
-Not malleable

Question 30

What are chemical families and/or groups?

Answer 30

-Chemical families are the vertical columns on the periodic table
-They are groups of elements with similar properties
-Elements in the same family will react in the same way

Question 31

What are the four groups and/or families?

Answer 31

1. Alkali Metals
2. Alkaline Earth Metals
3. Halogens
4. Noble Gases

Question 32

What are Alkali Metals and what are some examples?

Answer 32

-Extremely reactive metals
-Can react in air
-React violently with water
-Most reactive group of metals
Examples are Lithium, Potassium, Sodium, etc.

Question 33

What are Alkaline Earth Metals and what are some examples?

Answer 33

-Slightly less reactive than Alkali metals
-Very reactive in air and water
Examples are Beryllium, magnesium, calcium, etc.

Question 34

What are Halogens and what are some examples?

Answer 34

-Rarely found as elements because they are extremely reactive
-Most reactive group of nonmetals
Examples are Fluorine, bromine, chlorine, etc.

Question 35

What are Noble Gases and what are some examples?

Answer 35

-Extremely unreactive
-Very stable
-Gases
-Nonmetals
-Often used in light bulbs because they are so unreactive
Examples are Helium, neon, argon, krypton, xenon, and radon

Question 36

Classify the following elements as metals, nonmetals, or metalloids according to their properties.
1. At room temperature, this solid can be hammered and shaped into many different molds.
2. This elemental gas can be blown into a balloon but can never be used to conduct electricity.
3. This element makes up half of a salt molecule. It will conduct electricity on its own and can be easily bent and shaped.
4. This element is a solid that can be used for electrical conductors. However, it cannot be stretched into wires.

Answer 36

1. Metals
2. Nonmetal (Helium)
3. Metal (Sodium)
4. Metalloid (Silicon)

Question 37

What are periods?

Answer 37

The horizontal rows in the periodic table.

Question 38

What can we use the periodic table for?

Answer 38

-Learning the names of elements
-But the numbers tell us many things, especially about the subatomic particles