Compounds Atoms Mixtures

Question 1

What is a mixture?

Answer 1

A combination of two or more substances that can be separated by physical methods.

Question 2

What factors determine the method used to separate mixtures?

Answer 2

The type of mixture and the substances that make it up.

Question 3

What method is used for separating two solids, one of which is magnetic?

Answer 3

Magnetic separation.

Question 4

What method is used for separating two solids where one is more soluble than the other?

Answer 4

Dissolve in solvent and filter.

Question 5

What method is used for separating a solid and a liquid?

Answer 5

Filter.

Question 6

What method is used for separating a solid dissolved in a solvent?

Answer 6

Evaporation.

Question 7

What method is used for separating two liquids with different boiling points?

Answer 7

Distillation.

Question 8

What method is used for separating two solids with different solubility?

Answer 8

Chromatography.

Question 10

What are physical changes?

Answer 10

Physical changes are changes that matter can undergo without altering its chemical composition.

Question 11

What are chemical changes?

Answer 11

Chemical changes involve matter changing from one type of substance to another, either by combining substances or breaking them apart.

Question 12

How can you identify a chemical change?

Answer 12

A chemical change can be identified by:
• A change in colour
• Gas being released
• Heat being released or absorbed
• Light being released

Question 13

Are chemical changes easy to reverse?

Answer 13

Chemical changes are usually very difficult to reverse.

Question 14

Give an example of a chemical change.

Answer 14

A piece of paper is burned, releasing light and heat and producing ash and other gases.

This illustrates a chemical change due to combustion.

Question 15

What happens to cake ingredients during baking?

Answer 15

The ingredients of a cake are mixed and put in an oven, changing chemically to form a cake that looks different from the individual ingredients.

This is an example of a chemical change.

Question 16

What occurs when petrol is burned in a car engine?

Answer 16

Petrol is burned in the engine, releasing light, heat, and sound, which drives the pistons and allows the car to move.

This demonstrates a chemical change through combustion.

Question 17

What is diffusion?

Answer 17

Diffusion is the process by which particles move from an area of higher concentration to an area of lower concentration.

Question 18

How does diffusion explain the spreading of a smell?

Answer 18

A smell can spread from one place to another because it consists of particles in the air.

Question 19

What happens when you swish a paintbrush in water?

Answer 19

The color spreads throughout the water in the container, and this happens faster if the brush is swished around.

Question 20

What is gas pressure dependent on?

Answer 20

Gas pressure depends on the amount of particles that make up the gas and the kinetic energy of those particles.

Question 21

Why can you inflate a balloon?

Answer 21

You can inflate a balloon because you are forcing more particles into the space inside the balloon.

Question 22

What happens to the pressure inside a rugby ball when you inflate it?

Answer 22

The pressure inside the rugby ball increases as more gas particles are forced into it, causing them to bounce into each other more often.

Question 23

What occurs when you compress a gas?

Answer 23

Compressing a gas increases the pressure because there are more particles in a smaller space.

Question 24

What is a physical change?

Answer 24

A physical change is a change that can occur without altering the substance’s chemical composition.

Question 25

What is a chemical change?

Answer 25

A chemical change involves the transformation of one type of substance into another by combining two or more substances.

Question 26

How can you tell if a chemical change has occurred?

Answer 26

Signs of a chemical change include gas production, heat release, and light emission.

Question 27

What is an example of a chemical change?

Answer 27

A piece of wood burning is an example of a chemical change.

Question 29

What are the properties of solids?

Answer 29

Solids keep their shape and do not flow like liquids. They always take up the same amount of space and can be cut or shaped. ## Footnote Even though they can be poured, sugar, salt, and flour are all solids. Each particle of salt, for example, keeps the same shape and volume.

Question 30

What is the kinetic energy of particles in solids?

Answer 30

The particles that make up solids have the lowest kinetic energy of the three states.

Question 31

What are the properties of liquids?

Answer 31

Liquids can flow or be poured easily and change their shape depending on the container. They always take up the same amount of space, and their volume stays the same. ## Footnote The particles that make up liquids have kinetic energy in between solids and gases.

Question 32

What are the properties of gases?

Answer 32

Gases are often invisible, do not have a fixed shape, and spread out to fill the container. They can be compressed to take up less space. ## Footnote The particles that make up gases have the highest kinetic energy of the three states.

Question 33

What are elements?

Answer 33

Elements are substances that are only made up from one type of atom.

Question 34

What are compounds?

Answer 34

Compounds are substances made up from two or more types of atom chemically bonded together.

Question 35

What are mixtures?

Answer 35

Mixtures are substances made up from two or more types of atom, or compound, not chemically bonded together.

Question 36

How many elements do you need to be familiar with for the first 20 elements on the periodic table?

Answer 36

You will need to be familiar with the first 20 elements (H - Ca).

Question 37

What do you need to remember about the first 20 elements?

Answer 37

You will need to remember the names and symbols, as well as how to draw each one.

Question 38

Are mixtures easier or harder to separate than compounds?

Answer 38

Mixtures are usually easier to separate than compounds.

Question 39

What are some compounds you will use in the lab this year?

Answer 39

Hydrochloric acid, Sulfuric acid, Sodium hydroxide, Water, Sodium chloride, Copper sulfate.

Question 40

What is the chemical formula for Hydrochloric acid?

Answer 40

HCl

Question 41

What is the chemical formula for Sulfuric acid?

Answer 41

H2SO4

Question 42

What is the chemical formula for Sodium hydroxide?

Answer 42

NaOH

Question 43

What is the chemical formula for Water?

Answer 43

H2O

Question 44

What is the chemical formula for Sodium chloride?

Answer 44

NaCl

Question 45

What is the chemical formula for Copper sulfate?

Answer 45

CuSO4

Question 46

How can the chemical properties of compounds differ from their elements?

Answer 46

The chemical properties of compounds can be much different from the chemical properties of the elements that make them up.

Question 47

Give an example of a compound and its dangerous elements.

Answer 47

Salt (NaCl) is stable and safe, but its elements, sodium (Na) and chlorine (Cl), are extremely dangerous.

Question 48

What is the symbol for the element oxygen?

Answer 48

O

Question 49

What is the atomic number of oxygen?

Answer 49

8 ## Footnote The atomic number indicates the number of protons and electrons.

Question 50

What is the atomic mass of oxygen?

Answer 50

16 ## Footnote The atomic mass is the sum of protons and neutrons.

Question 51

How do you calculate the number of neutrons?

Answer 51

Subtract the atomic number from the atomic mass. ## Footnote Example: 16 (atomic mass) - 8 (atomic number) = 8 neutrons.

Question 52

What is the number of protons in oxygen?

Answer 52

8

Question 53

What is the number of electrons in oxygen?

Answer 53

8

Question 54

How do you draw an atom?

Answer 54

Draw a circle for the nucleus and write the number of protons and neutrons next to their symbols.

Question 55

How many electrons can the first shell hold?

Answer 55

2

Question 56

How many electrons can the subsequent shells hold?

Answer 56

Up to 8 electrons.

Question 57

What should you do after filling the first shell?

Answer 57

Keep adding shells until all of the electrons are added.

Question 58

What symbols can be used for protons and neutrons?

Answer 58

p = 8 for protons and n = 8 for neutrons.

Question 59

What are the two types of sub-atomic particles in the nucleus?

Answer 59

Neutrons and protons.

Question 60

What charge do protons have?

Answer 60

Protons have a positive charge.

Question 61

What charge do neutrons have?

Answer 61

Neutrons have no charge.

Question 62

What is the symbol for protons?

Answer 62

The symbol for protons is 'p'.

Question 63

What charge do electrons have?

Answer 63

Electrons have a negative charge.

Question 64

How do electrons behave in relation to the nucleus?

Answer 64

Electrons orbit the nucleus at great speeds.

Question 65

What is the approximate distance of electrons from the nucleus if the nucleus were the size of an orange?

Answer 65

Electrons would be over 20 km away.

Question 66

What role do electrons play between atoms?

Answer 66

Electrons are responsible for creating the bonds between atoms.

Question 67

What is the mass of a single proton?

Answer 67

A single proton has a mass of 1.7 x 10^-27 kg.

Question 68

What is the relative mass of protons and neutrons?

Answer 68

Protons and neutrons have a relative mass of 1.

Question 69

What is the relative mass of electrons compared to protons?

Answer 69

Electrons have a mass of 1/2000th of protons.

Question 70

What is the charge of a neutron?

Answer 70

Neutrons are neutral.

Question 71

What is the charge of an electron?

Answer 71

Electrons have a negative charge.

Question 73

What should be decided before starting an experiment in the laboratory?

Answer 73

Decide which apparatus to use and assess any hazards in the laboratory.

Question 74

What is important when using materials and equipment in the laboratory?

Answer 74

Use a range of materials and equipment and control risks.

Question 75

What is diffusion?

Answer 75

The movement of particles from an area of high concentration to an area of lower concentration.

Question 76

What is an element?

Answer 76

Substances that are only made up from one type of atom. ## Footnote Example: Oxygen (O) is an element.

Question 77

What is a compound?

Answer 77

Substances made up from two or more types of atom chemically bonded together. ## Footnote Example: Water (H2O) is a compound.

Question 78

What is a mixture?

Answer 78

Substances made up from two or more types of atom, or compound, not chemically bonded together. ## Footnote Example: Air is a mixture.

Question 79

What is a solute?

Answer 79

A substance dissolved into water or another solvent.

Question 80

What is a solvent?

Answer 80

A liquid substance that other substances can dissolve into.

Question 81

What is a solution?

Answer 81

The combination of a solute and a solvent.