Topic 2- States of Matter and Mixtures

Question 1

Describe Solid

Answer 1

• strong forces of attraction between particles
• fixed postition
  -regular lattice arrangement
• definite shape and volume
• not much energy
• can only vibrate around a fixed postion
• the hotter the faster they vibrate ( reason why solids expand slightly when hot)

Question 2

Describe Liquid

Answer 2

• some force of attraction free to move past each other, but tend to stick together
  -no definite shape but definiate volume
• particles have more energy than solids
• particles constantle moving with random motion
  expands slightly when heated bc particles move faster

Question 3

Describe Gas

Answer 3

• no force of attraction
  free to move
  only interact when the particles collide
• no definite shape or volume
• when particles bounce off a wall they exert a pressure onto wall
• particles have the most energy
• particles move constantly with random motion
• gases either expand or their pressure increases when heated

Question 4

Solid to Liquid

Answer 4

• Melting
  when solid is heated particles gain more energy + vibrate more which weakens forces that hold them together
  at a certain tem the particles gain enough energy to brek free from their position

Question 5

Liquid to Gas

Answer 5

• Evaporating
  when a liquid is heated particles gain even more enregy, energy makes particles fasterbwhich weakens/breks bonds holding liquid together

Question 6

What happens to atoms in chemical changes

Answer 6

-atoms are rearranged
-bonds between atoms break and atoms change places
chemical changes are hard to reverse

Question 7

What is pure

Answer 7

• something that is completely made up of one element or compound

Question 8

What is a mixture?

Answer 8

• something that has more than one compound present
  e.g air

Question 9

Difference between pure and impure substaces?

Answer 9

• Pure substances have a specific melting and boling point
  -Impure substances melt and boil over a range of temps

Question 10

Difference between fractional and simple distillation

Answer 10

• Simple distillation is used for solutions
• Fractional distillation is used to separate a mixture of liquids

Question 11

How is water purified

Answer 11

1. Filtration- large particles like twigs and gravel are filtered out of water
2. Sedimentaion- iron sulfate or aluminium sulfate is added to water which makes particles clump together and settle at bottom
3. Chlorination- chlorine gas is bubble through to kill harmful bacteria and other microbes