Chemical Changes

Learning Intentions…

… that Bunsen burners are used to heat materials.

… to adjust Bunsen burner flames, and choose the right one for heating.

… to use a flame test to find out what is in a powder.

… to be careful when using gas.

1. Put on your safety glasses.2. Place the Bunsen burner on a heat-proof

mat.3. Push the rubber tube onto the gas tap.4. ALMOST CLOSE the air hole.5. Hold a lighted splint over the top of the

Bunsen burner – about 2 cm above.6. Turn on the gas tap slowly.

Name of Substance Colour of Flame

Lithium

Calcium

Barium

Potassium

Sodium

Substance X

Learning Intentions…

… to describe what happens when some materials are heated or cooled.

… that heating or cooling some substances can cause them to change.

… to understand the idea of reversible changes.

… to distinguish between reversible and irreversible changes.

Lets Play….

True or False?

IrreversibleTRUE

FALSE

Choose Now!

FALSE

Irreversible TRUE

FALSE

Choose Now!

FALSE

Irreversible TRUE

FALSE

Choose Now!

TRUE

Irreversible TRUE

FALSE

Choose Now!

TRUE

Irreversible TRUE

FALSE

Choose Now!

TRUE

Changing State

Learning Intentions… … that some substances are soluble and others are

insoluble.

… that insoluble substances can be separated by filtering.

… that soluble substances can be recovered by evaporation

… to understand that these changes are reversible.

… to develop the idea of sizes of particles, and use this to explain why different methods of separation are needed.

… to appreciate the healing effects of medicines.

… to determine a ‘best buy’ for a specific product.

Abracadabra!

Dissolving things – some definitions

If a substance CAN be dissolved it is called __________

If a substance CANNOT be dissolved it is called _________

Words – soluble, solute, solvent, solution, insoluble

Solubility words

Solute

Solution

Solvent

Saturate

d

Solubilit

y

How much of something that can be dissolved is

called…

A solution that CAN’T dissolve anything else is…

The solid that will be dissolved is the…

The mixture of solute and solvent is called the…

The liquid that the solute will be dissolved into is

the…

Learning Intentions…

… that school science can be related to jobs in the outside world

…to plan a scientific investigation.

… to carry out a scientific investigation

.… to report on a scientific investigation.

Learning Intentions… … that when materials burn a flame can be seen.

… that heat causes chemical changes.

… that in chemical changes new substances are formed, some of which may be invisible.

… that safety is essential when heating or burning materials.

Lets Play….

All

Mixed

Up

Another word for burning is…..

M

C

O

B

U

S

TI

O

N

COMBUSTION

Learning Intentions… … that fire happens when a material burns.

… that fire needs oxygen, fuel and heat energy, and that fires can be put out by removing one of these essential things.

… that fire under control can be very useful, but we need protection from its harmful effects.

… that, as responsible young people, we can protect our environment from fire devastation.

FuelsFuels are substances that can be used to release useful amounts of energy when they burn, e.g.

Oil GasWood

Burning thingsWhen something is burned it reacts with oxygen. For example:

Magnesium + oxygen Magnesium oxide

Carbon + oxygen Carbon dioxide

Sulphur + oxygen Sulphur dioxide

The Fire Triangle

Fire

Fuel

Oxy

gen

Heat