Properties of Materials

Question 1

What are the freezing, boiling and melting points?

Answer 1

Freezing point: The temperature at which a liquid becomes a solid eg. water to ice at 0C
Boiling point: The temperature at which a liquid becomes a gas eg. water to steam at 100C
Melting point: The temperature at which a soild becomes at liquid eg. ice to water at 0C

Question 2

What is diffusion?

Answer 2

The spreading of particles to fill the space theyre in

eg. spraying perfume

Question 3

What are the physical and chemical properties of materials?

Answer 3

Physical: can be observed without changing t substance eg. colour, smell
Chemical: the way it reacts when new substances are made eg. magnesium burns oxygen to form a new compound magnesium oxide

Question 4

What is a solute and a solvent?

Answer 4

Solute: Substance which dissolves in the liquid eg. sugar
Solvent: Liquid in which the substance dissolves in eg. water

Question 5

What is a solution and a saturation solution?

Answer 5

Solution: mixture of a solute and a solvent eg. mixture of salt and water=salt water solution
Saturation solution: when as much solute as possible is dissolved in a solution at a given temperature.

Question 6

What is crystallisation?

Answer 6

When a hot saturated solution is cooled slowly over long time and crystals form.

Question 7

What is concentrated solution and a diluted solution?

Answer 7

Concentrated: a lot of solute, less solvent
Diluted: A lot of solvent, less solution

Question 8

What is solubility and the factors the affect it?

Answer 8

• A measure of the ability of a substance to dissolve another substance
• Temperature of solvent, particle size of solute, type of solvent used

Question 9

What are conductors and insulators?

Answer 9

Conductors: allow heat and electricity to flow through them eg. metals
Insulators: do nit allow heat or electricity to pass through them eg. wood

Question 10

Look at experiments!

Answer 10

:)

Question 11

Reactants and Products

Answer 11

Reactants: compounds of left hand of equation
Products: compounds of right hand of equation

Question 12

Types of reactions

Answer 12

Endothermic: take in heat as energy
Eg. Sodium chloride

Exothermic: give out energy as heat
Eg. Sodium hydroxide pellets

Question 13

What is activation energy and energy profile diagrams

Answer 13

• the minimum energy needed for a reaction to take place
• X-axis = time // Y-axis energy of reaction
• Endothermic: reactants energy is less than product energy
• Exothermic: reactants energy is higher than product energy