MATTER AND ENERGY
What is matter?
Matter is everything around us, from
the air we breathe to the chair you are sitting on. Matter exists in 3 states: solid, liquid and gas.
SOLIDS
Solids have their own shape. If you
move a solid to a different place, it‘s
shape doesn‘t change.
A bag, pencils, plants and animals are solids
LIQUIDS
Liquids don‘t have their own shape.
They take the shape of the container they are in. For example, the orange juice
takes the same shape as the jug or the glass
Juice, oil, milk and the sea are liquids
GASES
Gases don‘t have their shape either.
They take the sahpe of the container they are in. Gases fill the container, for
example, gas fills the balloons.
The air we breathe and the gas we cook with are gases
Properties of matter
All
objects have mass and a volume. Mass is the amount of matter an
object contains. Volume is the space the object occupies.
A car has a mass of 2.000 kilograms
and the bag of sugar has a mass of 1 kilogram. This means the car has a bigger
amount of matter tan the bag.
The summing pool has a volume os
100.000 litres and the carton of milk has a volume of 1 litre. The swimming pool occupies more
space than the carton.
What makes matter change?
When an object changes but the
matter it is made of doesn‘t change, it is a physical change.
When we change the shape of an
object, its matter doesn‘t change. We make paper planes, but the paper is still
paper.
When we change the place of an
object, its matter doesn‘t change. The bicycle moves to a different place, but
is still a bicycle.
When we change the temperature
of an object, its matter doesn‘t change. We warm milk, but it is still milk.
When an object changes state,
its matter doesn‘t change, We freeze water to make ice, but it is still water.
When
an object changes and different matters forms, it is a chemical change.
When an Apple rots, different
matter forms.
When milk ferments, it changes
to yoghurt. Milk and yoghurt are different matters.
When iron rusts, different
matter forms.
When Wood burns, it changes to
ash. Wood and ash are different matters.
What happens when you mix differenr types of
matter?
In
some mixtures you can see each of the components separately. These are called heterogeneous mixtures.
When we put chickpeas in water and stir, we make a heterogeneous mixture. We can still see the water and the chickpeas
separately.
In
other mixtures you can‘t see each of the components separately. The whole
mixture looks the same. These are called homogeneous mixtures.
When we put sugar in water and stir, we make a homogeneous mixture. We can‘t see the sugar and water separately
anymore.
Two ways of separating mixtures (DON‘T STUDY)
Evaporation separates a homogeneous
mixture of liquid and solid:
·
Leave the mixture in a shallow
dish.
·
The water evaporates.
·
The salt stays on the
plate.
Filtration separates
a heterogeneous mixture of a liquid and a solid.
·
Pour the mixture into a
funnel.
·
The water passes throug
the funnel.
·
The sand stays in the
funnel.
Forms of Energy
Everything we do needs energy
We use
energy to do homework, to play, to heat our houses and to move a car.
Living and non-living things need
energy. Non-living things need energy to work.
TOOLS
·
Use energy from people
moving them
·
Most machines use energy
from electricity. Most means of transport use energy from burning fuel.
SOURCES OF ENERGY
The energy that we use every day
comes from non-renewable and renewable sources.
NON-RENEWABLE ENERGY SOURCES
·
Coal, petroleum and
natural gas are natural matter. They were formed under the ground a very long
time ago.
·
They are limited and
they will run out in the future.
RENEWABLE ENERGY SOURCES
·
The sun, wind, water and
biomass are renewable sources of energy.
·
There is always new
wind, sunlight, water and biomass.
·
They are unlimited and
they will never run out.
·
They don‘t pollute the
air or water.
·
Solar energy comes from
sunlight.
·
Wind energy comes from
moving air.
·
Hidroelectric
energy comes from moving water.
·
Bioenergy comes from
burning organic matter from plants, called biomass.
