Chemical change

Question 1

Sublimation

Answer 1

A solid changing into gas

Question 2

Melting

Answer 2

A solid changing into liquid

Question 3

Evaporation

Answer 3

Liquid changing into gas

Question 4

Freezing/Solidification

Answer 4

Liquid changing into a solid

Question 5

Condensation

Answer 5

gas turning into liquid

Question 6

Solid

Answer 6

firm and stable in shape because its particle are close together.

Question 7

Liquid

Answer 7

a substance that flows freely but is of constant volume because of its particles being further away

Question 8

Gas

Answer 8

state of matter with no fixed shape or volume

Question 9

Deposition/Desublimation

Answer 9

Gas turning into a solid

Question 10

physical properties

Answer 10

properties that you can either observe using your five senses — seeing, hearing, touching, smelling and tasting — or measure directly

Question 11

chemical properties

Answer 11

properties that describe how a substance combines with other substances to form new chemicals or how a substance breaks up into two or more different substances

Question 12

flammability

Answer 12

an indicator of how easily a substance catches fire

Question 13

reactivity

Answer 13

a measure of how likely a particular metal is to take part in a displacement reaction

Question 14

toxicity

Answer 14

the danger to your health caused when poisonous substances combine with chemicals in your body to produce new substances and damaging effects

Question 15

reaction rate

Answer 15

speed at which a reaction takes place

Question 16

catalyst

Answer 16

chemical that helps to start or speed up a chemical reaction

Question 17

rusting

Answer 17

the corrosion of iron

Question 18

corrosion

Answer 18

a chemical reaction that wears away a metal. Air, water or chemicals in air and water, as well as many household substances, can be corrosive. Many acids and other corrosive substances are dangerous.

Question 19

rust

Answer 19

a brown substance formed when iron reacts with oxygen and water

Question 20

burning

Answer 20

combining a substance with oxygen in a flame

Question 21

oxidation

Answer 21

chemical reaction involving the loss of electrons by a substance

Question 22

fossil fuel.

Answer 22

substance, such as coal, oil and natural gas, that has formed from the remains of ancient organisms. Coal, oil and natural gas are often used as fuels; that is, they are burnt in order to produce heat

Question 23

combustion

Answer 23

the process of combining with oxygen, most commonly burning with a flame