Mixtures & Matter Summary

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SCIENCE

TOPIC TEST 1 REVISION: MIXTURES & MATTER

SECTION

ONE: Matter, particles and solutions

SLO

01: Describe how

matter is made up of particles

A

particle is the smallest object that anything can be broken up into.

Everything which has mass and occupies space (matter) is made up of

particles

SLO

02: Use

particles to classify matter

as pure substances and mixtures

Pure

substances are only made up of one type of particle, whereas

mixtures are a combination of two or more types of particles.

SLO

03: Define the

words solution, solvent, solute, soluble, insoluble and saturated.

Solution:

A combination of a solvent and a solute.

Solvent:

The substance that dissolves the solute.

Solute:

The substance that is dissolved by the solvent.

Soluble:

When a substance can be dissolved in a solvent.

Insoluble:

When a substance cannot be dissolved in a solvent

Saturated:

The point where the solute is no longer able to dissolve in the

solvent

SLO

04: Use

particle diagrams to distinguish between

dilute and concentrated solutions

Dilute:

In a dilute solution, there is far more solvent particles than solute

particles.

Concentrated:

In a concentrated solution, there is still more solvent particles

than solute particles, but the difference between them wouldn’t be

as significant.

SLO

05: Define the

term saturated solution and describe how

solubility changes with temperature.

A

solution is saturated when it’s up to the point where the solute

can no longer dissolve in the solvent. Solutes can dissolve faster in

a solvent when the solution is heated because hot

water has

more energy than cold water.

When water is

heated, the molecules gain energy and move faster.

As they move faster,

they come into contact with the sugar more often, causing it

to dissolve

faster.

SECTION

TWO: Separating mixtures

SLO

06: Describe and distinguish between chemical

change and physical change

Chemical

change is when the substance changes into a completely different

substance, whereas physical change in a substance doesn’t change

what the substance is. Eg: Water freezing and changing to ice is a

physical change, iron rusting is a chemical change.

SLO

07: Name, draw and describe a

variety of common scientific apparatus including: Bunsen

burner, filter

funnel, clamp stand, test-tube, flask, tripod

and gauze, beaker, boiling tube, tongs, test-tube

holder and burner

board.

Bunsen

burner: A flame which is fuelled on gas.

Filter

funnel: A glass/ plastic funnel to use with filter paper for

filtering.

Clamp

stand: Used to hold test tubes.

Test-tube:

A glass tube to hold liquids for experiments in the lab.

Flask:

Made of glass, used to hold or mix liquids. Is useful for mixing

because it has a large body and narrow neck to avoid spills.

Tripod:

A stand with three “legs” used to hold beakers up above the

Bunsen burner to heat up.

Gauze: A small piece of mesh placed

on a tripod to

support the beaker/glass and distribute heat evenly.

Beaker:

A glass cup to hold and measure liquids.

Boiling

tube: A larger test tube that can withstand more heat.

Tongs:

A hand clamp that can be used to hold a variety of object in the lab

if it’s unsuitable to touch.

Test-tube

holder: Similar to tongs but can only hold small objects such as test

tubes.

Burner

board: A thin board made of fireproof and heatproof material for the

Bunsen burner and tripod to stand on.

SLO

08: Describe how

a variety of common mixtures are separated using one or more of the

following

techniques: decanting, filtering, evaporation, distillation, magnetism and chromatography.

Decanting:

A mixture is left to settle until the denser substance settles at the

bottom. Then the less dense substance is poured into another

container, leaving the denser substance behind.

Filtering:

A mixture is poured into a filtering tube with filter paper- the

substance with smaller particles will go through the filter paper

while the substance with larger particles is left on the paper.

Evaporation:

The liquid is left to evaporate (or boiled), leaving the substance

that can’t be evaporated behind. The liquid can be recovered by

condensation.

Distillation:

The mixture is boiled and whichever liquid boils first is collected

through a tube to a separate container. The liquid which hasn’t

boiled yet is left in the first container.

Magnetism:

Materials can be magnetised will stick to the magnet, separating it

from other materials

Chromatography:

Samples of the mixture is put on chromatography paper and the end of

the paper is dipped into water. The water will climb up the paper,

taking particles in the mixture with it. The larger particles will be

slower to climb up the paper while the smaller particles will climb

higher, separating itself from the larger particles.

SLO

09: Define the

term physical

property and explain how

differences in physical properties enable mixtures to be separated

Physical

properties are the characteristics of an object that can be observed

without changing what it’s made of, eg. Colour, density, shape…etc.

Physical properties enable mixtures to be separated- eg. If one of

the substances in a mixture is denser than the other, it can be

separated using decanting.

SECTION

THREE: The particle model of matter

SLO

10: Name the

three states of matter and draw a

simple particle diagram for each state.

The

3 states of matter are: Liquid, solid and gas. The particles in a gas

are very far apart, the particles in a liquid are not as far apart

and the particles in a solid are very compact.

SLO

11: Relate the

physical nature of each state of matter (shape,

pourable and compressible) to the strength of forces acting between

particles.

Particles in a solid are pulled together by a very strong force, so solids have a fixed shape, volume and are very difficult to compress. Particles in liquids are pulled together by a force which isn't as strong as a force in a solid, so liquids have a fixed volume but not a fixed shape, therefore its shape depends on the container it is being stored it. Liquids are easier to compress than solids. Gas particles are pulled together by a very weak force, so it has no fixed shape or volume. Gases are the easiest to compress compared to solids and liquids.

SLO

12: Describe the

process of diffusion and apply it

to different contexts.

Diffusion is the process of particles in a high area of concentration moving to an area of low concentration to balance the spread of particles

SLO

13: Use

particles to describe how

soluble solids dissolve into solution

When a solid come into contact with a liquid, the particles of the solid may start to come apart and mix with the particles of the liquid. This is the process of dissolving

SECTION

FOUR: Matter and Heat

SLO14: Distinguish between

heat energy and temperature

Heat

energy is the movement of particles moving. Temperature is the

measure of the average heat of the particles in a substance

SLO15: Name the

processes that describe changes in state.

Processes

include melting, boiling (or vaporisation), evaporation, sublimation,

condensation, freezing (or solidification), reverse sublimation (or

deposition).

SLO16: Explain change

in state in terms of particle movement and breakdown/formation of

forces between particles.

When

more energy is absorbed by the particles in a substance, they gain

kinetic energy and start to move faster and away from each other.

This results in a change of state. Eg. From a solid to a liquid. When

energy is released by the particles in a substance, they lose kinetic

energy- their movement will slow down and the particles will start

packing themselves tighter together. This also results in a change of

state. Eg. From a liquid to a solid.

SLO17: Explain using

particles and energy, why solids, liquids and gases expand when

heated and contract when cooled (but particle size remains

unaffected).

When

particles in a substance are heated, they gain kinetic energy and

will move faster and the space between the particles will increase.

This results in the substance expanding. On the other hand, if

particles in a substance are cooled, they lose kinetic energy. Their

movement will slow down and the particles will pack themselves

tighter together. This results in the substance contracting.

SLO18: Discuss applications

and effects of thermal expansion and contraction