States of matter and atoms

Question 1

States of matter

Answer 1

SOLID:

• particles close together
• regular pattern
• vibrate on the spot
• low kinetic energy

LIQUID:

• close together
• random arrangement
• move around each other
• increased kinetic energy

GAS:

• far apart
• random arrangement
• move quickly in all directions
• high kinetic energy

Question 2

State changes

Answer 2

1. Heat supplied
Melting: solid → liquid 
Evaporating/boiling: liquid → gas
-particles spread out 
-arrangment becomes more random
-KE increases

2. Heat removed
Condensing: gas → liquid
Freezing: liquid→ solid
-particles closer together
-arrangement more regular
-KE decreases

3. Heat applied under certain conditions
   Sublimation : solid → gas
   e.g ‘dry ice’ to carbon dioxide
4. Changing pressure
   Liquefy: gas → liquid
   -particles are moved close enough for bonds to from between particles

Question 3

What is a solution?

• examples
• movement of particles

Answer 3

When a solute(soluble solid compound ) dissolved into a solvent (liquid)

Examples

1. Sodium chloride(white) dissolved in water→ colourless liquid
2. Copper sulphate(blue) in water→ blue liquid
3. More water added (more dilute→ paler colour

Movement of particles:

• individual particles break apart and spread out though out the water
• particles are now too small to see and evenly spread out
• particels even further apart

Question 4

Atoms

Answer 4

The smallest particles in an element

Question 5

Molecules

Answer 5

A cluster of non-metal atoms that are chemically bonded together

Question 6

Element

Answer 6

A pure substance listed on the Periodic Table and only has one type of atom in it

Question 7

Compound

Answer 7

A (pure) substance made from more than one type of element chemically bonded together
(Will take a chemical reaction to separate)

e.g water, carbon dioxide

Question 8

Mixture

Answer 8

An (impure) substance made from different elements or compounds
(each substance is easily separated)

e. g air
note: NOT chemically bonded together

Question 9

Diffusion

Answer 9

GAS: quick as particles in gas move quickly
e.g spraying perfume in one part of a room

LIQUID: slower as particles move slower but will eventually spread out

SOLID: does not happen as particles do not move, only vibrate

Question 10

Simple Distillation

Answer 10

Liquid separated from a solution

e. g salty water :
- water evaporated off
- condensed
- water left
- salt left

Question 11

Fractional distillation

Answer 11

Two or more liquids separated from each other

e. g ethanol/ water solution:
- solution boiled
- ethanol evaporates first due to lower boiling point
- ethanol condensed
- water evaporates, condensed
- etanol/water left

Question 12

Filtration

Answer 12

Insoluble solid from a liquid

e. g sand in water:
- liquid poured through filter
- water funnelled into beaker
- sand left in filter paper
- water/sand left

Question 13

Crystallisation

Answer 13

Product separated when made as a solution

e. g sugar solution
- evaporate the solution into smaller volume
- leave to cool
- crystals form

Question 14

Paper chromatography

Answer 14

Separate mixtures of coloured compounds

e. g ink
- pencil line drawn across chromatography paper
- spot of ink placed near bottom of paper
- paper placed upright in water
- mixture carried up paper as solvent soaks in
- mixture components move at different rates separating out the mixture
- Ink components left