• All the materials around us can be changed in different ways.

• A physical change is when a material changes size, shape or state of matter.

• Physical changes are easy to reverse

Eg. Mixing sugar in tea

Boiling water

Melting ice cream

Melting wax

• A chemical change to a material results in a completely new material being made.

• A chemical change is very difficult to reverse.

Eg. Some rotting fruit

A rusting nail

Burning paper

Exploding a bomb

In a reaction:

• The stuff you start with is called the reactant

• The stuff you produce is called the product

Reactant

• For example:

Raw bread dough Bread

Bread Toast

ProductReaction

Simple Chemical Reactions

Baking

Toasting

The word equation for a chemical reaction is:

Reactants Products

The starting materials that react with each other are called the reactants.

The new materials that are produced by the

reaction are called the products.

Arrow means “reacts to make”

Chemical reactions• There are many changes happening all the

time, how can we tell if they are chemical?

In every chemical change, products (new substances) are made that are different from

the reactants (substances we started with).

Gas: Test for it:

Oxygen

Carbon dioxide

Hydrogen

Solute

Solvent

Solution

Soluble

Insoluble Something that is dissolved in a liquid

Something that is able to dissolve

A mixture formed when a solute dissolves in a solvent

A liquid that other substances will dissolve in

Something that is not able to dissolve

Filtration and Evaporation

A separation technique used to separate soluble substances from their solvents

A separation technique used to separate an insoluble substance and a liquid

Which is which?

Separating Mixtures

Separating Mixtures

Distillation

True or false• During evaporation water changes to steam• Distillation is condensation followed by

evaporation• Distillation can be used to prepare pure water

for science experiments• Condensation is when water changes into ice