1. MATTER
Matter is all around us such us
solid
liquid
gas
IMPORTANT DEFINITIONS:
MASS:How much matter an object has (kilograms,grams…)
VOLUME:The quantity of space that an object takes up.
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2. Solids,liquids,and gases
Matter is all around us .There are three states of matter:Solids,liquids and gases.
Solid have a definite shape and a definite volume because they take up the same a space .
Liquids don’t have a definite shape because they adapt to the shape of the container
they are in,but they have definite volume because they aways take up the same space.
Finally gases don’t have a definite shape because they adapt at the shape of the
container they are in and they don’t have definite volume because they expand to
fill the container they are in.
3. Physical changes
Physical changes can happen when we heat,freeze,bend,twist,
stretch or squash a substance,or when matter changes shape and
changes state but the subs tens doesn’t change.
Physical changes happen to water in the water cycle.
4. Chemical changes
A chemical change is when a new substance is produced.
Chemical changes happen when we burn a substance or
expose something to air.
5. Mixtures
We can classify mixtures as heterogeneous or homogeneous
mixtures.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.
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 roks and
oil come from minerals.
7. The three Rs
If we take too many of these natural resources,they will run out.This is
why is important to reduce,reuse and recycle.
We should try to reduce the amount of materials we use and the
waste we produce.
We can reuse many things .For example,we can reuse plastic
shopping bags.
Recycle means to make something new from something we have
used.
