2. MATTER IS ALL AROUND US
• There are three states of matter: solid, liquid and
gas.
– Solids have a definite shape and a definite volume
because they take up the same space.
– Liquids don’t have a definite shape but they always
take up the same space.
– Gases don’t have a definite shape because they adapt
to shape of the container they are in and they don´t
have a definite volume because they expand to fill the
container they are in.
3. CHANGES IN MATTER
• Physical changes happen when
matter changes shape and state but
the substance doesn’t change.
• Physical changes can happen .when
we heat, freeze, bend, twist, strech or
squash a substance.
• A chemical change is when a new
substance is produced.
• Chemical change can happen when
we burn a
substance or expose a substance to
air.
4. MIXTURES
• A mixture is something that contains two or more
substances.
• We can find examples of mixtures in nature. Air is a
mixture of gases. Saltwater in the sea, many rocks, etc…
• In a heterogeneous mixture it´s easy to see the different
substances. In a homogeneous mixture it isn´t possible
to see the different substances.
5. PROPERTIES OF MATERIALS
• A resistant material is difficult to break, but a fragile material
breaks easily.
• A rigid material doesn’t bend easily, but we can bend a flexible
material. An elastic material returns to its original shape.
• Light can pass through transparent material, but light can’t
pass through opaque materials. Water can pass through
permiable materials whereas water can’t pass through
waterproof materials.
• Heat passes through heat conductors but heat can’t pass
through heat insulators easily.
6. NATURAL AND MANUFACTURED
MATERIALS
• We can classify materials into natural materials and manufactured
materials.
• Natural materials come from nature and can come from plants,
animals or minerals.
• Wood, cotton and natural rubber come from plants. Wool, leather
and silk come from animals, and rocks and oil come from minerals.
• Manufactured materials are made from natural materials which are
transformed in a manufacturing process. We manufactured glass
from sand, and we use oil to make plastic, crayons and fabrics such
as nylon.
7. THE THREE RS
• If we take too many natural resources, they will run out. This is why it’s
important to Reduce, Reuse and Recycle.
• We should try to reduce the amount of materials we use and the waste
we produce. Buy products with little or no packaging, then put the
packaging in the correct recycling bin.
• We can reuse plastic shopping bags. We can clean packaging such as boxes
and jars and use them again.
• Recycle means to make something new from something we have used.
• We can recycle glass, plastic, aluminium, paper, cars,
electrical appliances, furniture and many more things too.
