UNIT 4 MATTER
THE PROPERTIES OF MATERIALS
· PHYSICAL
PROPERTIES
Hard: Difficult to scratch or cut
easily.
Soft: Easy to scratch or cut.
Tough:
Difficult to break.
Fragile:
Easy to break.
Plastic:
Easy to bend.
Elastic:
Go back to their shape after we squash or stretch them.
· SOLUBILITY
It describes if a material can dissolve in water.
Soluble:
Materials that dissolve.
Insoluble:
Materials that don´t dissolve.
· THERMAL CONDUCTIVITY
It describes if a material can get very hot.
Thermal
Conductors: Materials that can get hot.
Thermal
Insulators: Materials that don´t get hot.
THE
PROPERTIES OF MATTER
· VOLUME
It is the
amount of space that matter occupies.
Unit: Cubic
centimetres (cm³).
· MASS
It is the
amount of matter in an object.
Unit: Grams and
kilograms.
· DENSITY
It is the
amount of mass that there is in the volume of an object.
To find
out the density of an object, we divide its mass by its volume.
CHANGES
IN MATTER
· PHYSICAL
CHANGES
The composition
of the matter doesn´t change. Physical changes
can be reversed.Physical changes: shape, place, state and temperature.
· CHEMICAL
CHANGES
The composition
of the matter changes and new matter is formed.
MIXTURES
AND SOLUTIONS
•
MIXTURES
AND TYPES
When two substances are mixed together they form a
mixture.
There are
two basic types of mixture: a heterogeneous mixture and a homogeneous mixture,
In a heterogeneous
mixture we can see the separate substances
( For example: salad).
In a homogeneous
mixture we can´t see the separate substances ( For example: hot chocolate). This is
because one sustance dissolves into
the other. A homogeneous mixture where
one sustance dissolves in another is called solution (hot chocolate). The susbtance that dissolves
is called the solute (chocolate
powder) and the substance that dissolves it is called
the solvent (milk).
• SEPARATING
MIXTURES
Filtration: It is used to separate
an insoluble solid from a heterogeneous mixture. For
example: sand and water.
Evaporation:
It is used to separate a soluble solid from a homogeneous solution. For example:
salt and water.
Distillation:
It is used to separate a liquid from a solution or to separate two liquids. For example: alcohol
and water.