States of Matter

Question 1

what does the state of a material depend on?

Answer 1

the forces of attraction that are between the particles

Question 2

what are the three things the strength of the forces between particles differ with?

Answer 2

1. the material
2. the temperature
3. the pressure

Question 3

solids

Answer 3

• in solids, there are strong forces of attraction between particles, which holds them close together in fixed positions to form a very regular lattice arrangement
• the particles don’t move from their positions, so all solids keep a definite shape and volume, and don’t flow like liquids
• the particles vibrate about their positions
• the hotter the solid becomes, the more they vibrate (causing solids to expand slightly when heated)

Question 4

liquids

Answer 4

• in liquids, there is a weak force of attraction between the particles
• they’re randomly arranged and free to move past each other, but they tend to stick closely together
• liquids have a definite volume but don’t keep a definite shape and will flow to fill the bottom of a container
• the particles are constantly moving with random motion
• the hotter the liquid gets, the faster they moved and this causes liquids to expand slightly when heated

Question 5

gases

Answer 5

• in gases, the force of attraction between the particles is very weak
• they are free to move and are far apart
• the particles in gases travel in straight lines
• gases don’t keep a definite shape or volume and will always fill any container
• the particles move constantly with random motion
• the hotter the gas gets, the faster they move
• gases either expand when heated, or their pressure increases

Question 6

what do physical changes do to particles?

Answer 6

change their arrangement or energy

Question 7

what is the change from solid to liquid?

Answer 7

melting

Question 8

what is the change from liquid to solid?

Answer 8

freezing

Question 9

what is the change from liquid to gas?

Answer 9

evaporation

Question 10

what is the change from gas to liquid?

Answer 10

condensation

Question 11

what is the change from solid to gas?

Answer 11

sublimation

Question 12

what is the change from gas to solid?

Answer 12

deposition

Question 13

what is the process of changing of states?

Answer 13

1. when a solid is heated its particles gain more energy
2. this makes the particles vibrate more, which weakens the forces that hold the solid together - this makes the solid expand
3. at a certain temperature, the particles have enough energy to break free from their positions - this is called melting and the solid turns into a liquid
4. when a liquid is heated, again the particles get even more energy
5. this energy makes the particles move faster, which weakens and breaks the bonds holding the liquid together
6. at a certain temperature, the particles have enough energy to break their bonds - this is called evaporating and the liquid turns into a gas