topic 3

Question 1

a change of state requires

Answer 1

energy

Question 2

when a substance is melting or boiling, what increases

Answer 2

the internal energy, but the energy is used for breaking intermolecular bonds rather than raising the temperature

Question 3

when a substance is freezing or condensing, what is formed

Answer 3

bonds are formed between particles, which releases energy

Question 4

what is latent heat

Answer 4

the amount of energy needed to to change 1kg of it from one state to another without changing temperature

Question 5

for cooling, what is latent heat

Answer 5

the energy released by a change in state

Question 6

what is the specific latent heat called when changing between a solid and a liquid

Answer 6

specific latent heat of FUSION

Question 7

what is the specific latent heat called when changing between a liquid and a gas

Answer 7

specific latent heat of VAPORISATION

Question 8

a solid all the way to a gas is called

Answer 8

sublimating

Question 9

liquid to a solid is called

Answer 9

freezing

Question 10

solid to a liquid is called

Answer 10

melting

Question 11

liquid to a gas is called

Answer 11

boiling

Question 12

gas to a liquid is called

Answer 12

condensing

Question 13

describe solids (3)

Answer 13

• strong forces of attraction hold particles together
• in a fixed, regular arrangement
• particles don’t have much energy so only VIBRATE about their fixed positions

Question 14

describe liquids (4)

Answer 14

• there are weaker forces of attraction between particles
• particles are close together, but can move past each other and form irregular arrangements
• have more energy than particles in a solid
• move in random directions at low speeds

Question 15

describe gases (3)

Answer 15

• there are almost no forces of attraction between particles
• particles have more energy than in liquids or solids- they’re free to move
• constantly moving in random directions at speeds

Question 16

when gas particles collide with something what happens

Answer 16

they exert a force on it

Question 17

what is pressure

Answer 17

the force exerted per unit area

Question 18

colliding gas particles creates ….

Answer 18

pressure

Question 19

if you increase the temperature of a gas, what happens

Answer 19

you transfer energy into the kinetic energy stores of its particles

Question 20

so increasing the temp of a gas, what else increases

Answer 20

the average speed of its particles

Question 21

what does the density of an object depend on

Answer 21

what its made of and how the particles are arranged

Question 22

in a dense material how are the particles arranged

Answer 22

the particles are packed tightly together

Question 23

in a less dense material how are particles arranged

Answer 23

the particles are more spread out

Question 24

in a less dense material, compressing the particles has what effect on the particles

Answer 24

the particles would move closer together and it would become more dense

Question 25

in terms of density, solids are more dense than...

Answer 25

liquids

Question 26

in terms of density, gases are less dense than...

Answer 26

liquids

Question 27

what is density

Answer 27

the measure of the compactness of a substance-it relates to the mass of a substance and how much space it takes up

Question 28

what type of change is a change of state called

Answer 28

physical

Question 29

what is a physical change

Answer 29

when you end up with the same substance but in a different form

Question 30

in a change of state what happens to the mass

Answer 30

it is conserved