Chemical change chapter 8

Question 1

physical properties

Answer 1

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

Question 2

chemical properties

Answer 2

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 3

flammability

Answer 3

an indicator of how easily a substance catches fire

Question 4

reactivity

Answer 4

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

Question 5

toxicity

Answer 5

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

Question 6

Melting

Answer 6

make or become liquefied by heating

Question 7

Evaporation

Answer 7

Evaporation is the process of a substance in a liquid state changing to a gaseous state due to an increase in temperature

Question 8

Sublimation

Answer 8

When the surface layer of snow or ice turns into fog or steam without melting

Question 9

Freezing

Answer 9

below 0°C

Question 10

Solidification

Answer 10

is a phase change of matter that results in the production of a solid

Question 11

condensation

Answer 11

water which collects as droplets on a cold surface when humid air is in contact with it

Question 12

Solid

Answer 12

firm and stable in shape; not liquid or fluid.

Question 13

Liquid

Answer 13

a substance that flows freely but is of constant volume, having a consistency like that of water or oil.

Question 14

Gas

Answer 14

an air-like fluid substance which expands freely to fill any space available, irrespective of its quantity.

Question 15

deposition

Answer 15

the action of deposing someone, especially a monarch.

Question 16

Desublimation

Answer 16

is the phase change from gas directly to solid, with no intermediate liquid phase.

Question 17

reaction rate

Answer 17

speed at which a reaction takes place

Question 18

catalyst

Answer 18

chemical that helps to start or speed up a chemical reaction

Question 19

rusting

Answer 19

the corrosion of iron

Question 20

corrosion

Answer 20

a chemical reaction that wears away a metal

Question 21

rust

Answer 21

a brown substance formed when iron reacts with oxygen and water

Question 22

surface protection

Answer 22

coating over a metal surface to prevent corrosion

Question 23

galvanising

Answer 23

protecting a metal by covering it with a more reactive metal that will corrode first

Question 24

burning

Answer 24

combining a substance with oxygen in a flame

Question 25

oxidation

Answer 25

chemical reaction involving the loss of electrons by a substance

Question 26

fossil fuel

Answer 26

substance, such as coal, oil and natural gas, that has formed from the remains of ancient organisms.

Question 27

combustion

Answer 27

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