chapter 2

Question 1

describe arrangement of solids

Answer 1

• particles closely packed in an orderly arrangement
• very strong forces of attraction between particles

Question 2

describe movement of solids

Answer 2

• particles vibrate in fixed positions
• lowest energy level

Question 3

describe arrangement of liquids

Answer 3

• particles closely packed in a disorderly arrangement
• strong forces of attraction between particles

Question 4

describe movement of liquids

Answer 4

• **particles move within confined space **and rotate and slide past each other
• higher energy level than solid but lower than gas

Question 5

describe arrangement of gases

Answer 5

• particles are far apart in a disorderly arrangement
• weak forces of attraction between particles

Question 6

describe movement of gases

Answer 6

• particles move freely, rapidly, randomly in all directions
• highest energy level

Question 7

what happens when a solid is heated

Answer 7

1. particles gain KE and vibrate faster
2. particles overcome forces of attraction between them and** break away from fixed positions**
3. particles now slide over one another →melted to liquid

Question 8

what happens when a liquid is cooled

Answer 8

1. particles lose KE and move more slowly
2. particles form attractive forces between them and move into fixed positions
3. particles now move into fixed positions

Question 9

describe what happens on a heating curve
- gain in temp
- constant temp

Answer 9

gain in temp:

• particles gain KE and temp rises until melting point

constant temp:

• during melting, particles of solid gain energy and (state change in arrangement and movement of particles)
• there is no increase in temp as heat is used to overcome forces of attraction to separate particles

Question 10

describe what happens in a cooling curve
- lost in temp
- constant temp

Answer 10

lost in temp:
- lose KE
- when temp of liquid drops to freezing point, it starts to freeze

constant temp:
during freezing, particles lose energy and (state change in arrangement and movement of particles)

no decrease in temp as heat is released to the suuroundings when particles slow down to take up orderly and fixed positions in solid

Question 11

factors of diffusion

Answer 11

temp:
→ higher temp, particles move faster, faster rate of diffusion

Mr (relative molecular mass):
→ gases w lower Mr diffuse faster

methane: CH4 → 16

ammonia: NH3 → 17

Question 12

cotton wool qn: where does the white stuff travel towards?

Answer 12

→ the substance w lower Mr travels faster so the result is further awat from the lower Mr substance

Question 13

porous pot qn: what causes the water level to rise?

Answer 13

→ the gas w lower Mr will diffuse into porous pot faster than the gas w higher Mr diffusing out of the porous pot

→ net number of molecules in the pot increases, resulting in an increase in pressure in the pot and the water level is pushed up/down