UNIT 5

MATTER

FREEZING

• Liquid water cools down zero degrees Celsius.

• It changes into ice.

EVAPORATION

• Liquid water heats up.

• It changes into water vapour.

BOLILING

• Liquid water heats up one hundred degrees celsius or more.

MELTING

• Ice heats up.• It changes into

liquis water.

CONDENSATION

• Water vapour cools down.

• It changes from a gas into a liquid.

Water changes when it heats up or it cools down.These changes are reversible.

Oxygen molecule is an element because there is one kind of atoms.

Water molecule is a compound because there is two kinds of atoms.

MATTER

Matter is made of atoms. Atoms are the building blocks of matter.

Molecule: two or more atoms join together.

Element: only one kind of atom

Compound: atoms of different elements join together

atom molecule element compund

Solid: the molecules are very close together.

Liquid: the molecules aren’t so close together .

Gas: the molecules can move freely.

STATES OF MATTER

Melting: solid and heat liquid

Evaporation: liquid and heat gas

Solidification: liquid and cool solid

Condensation: gas and cool liquid

PHYSICAL CHANGESThe substance changes but the matter stays the same.

TEMEPRATURE

CHEMICAL CHANGES

Combustion: a substance is burned.New substance: ash and smoke.

Oxidation: a substance reacts with the oxygen in the air without burning.New substance: rust.

Putrefaction: organic matter decomposes.New substance: mould.

The substances changes into a different substance.

Pure substance: can be elements or compounds.Mixtures: are made up of two or more pure substances.

Mixtures

heterogeneous

It’s possible to separate the

substances easily.

homogeneous

We can’t see the individual

substances, but we can’t still separate

them.

•The solids stay in the filter, and the liquid passes through it.

Filtration•The

liquid evaporates and leaves only the solids.

•The solids crystallise and form crystals.

Evaporation

•We can use a magnet to attract the solids.

Magnetic separation

Ways to separate the mixtures