lesson one - unit one 1st preparatory science .

1. MATTER AND ITS
CHARACTERISTICS

2. MATTER:
 It is anything that has a
mass and volume.
 It is anything that has
a mass and occupies a space.

3. Objects are
distinguished
from each other by :
Physical properties Chemical properties

4. Physical properties:
 1- Colour ,taste and smell.
 2- Density.
 3- Melting point.
 4- Boiling point.
 5- Hardness.
 6-Electric conductivity.
 7- Thermal conductivity.

5. ** the colour ,taste and
smell:
To differentiate between gold and
iron we used co lour.
To differentiate between salt and
sugar we used Taste.
To differentiate between perfume
and vinegar we used smell.

6. DENSITY:
 MASS:
It is the amount
of matter that
the body
contains.
‫٭‬measured unit :
Kg -gm
 VOLUME:
It is the space
that a
substance
occupies.
‫٭‬measured unit :
cm3

7. DENSITY:
 It is the mass of unit volume of
matter.
 OR
 It is the mass of one cubic
centimeters of matter.

8.  Density=
M
D V
Mass
volume
Measuring unit:
gmcm3

9. Problems:

10. Note:
 Materials which have higher
density than water sink in it .
 Ex: iron – metallic- coin .
 Materials which have lower
density than water float on its
surface .
 Ex: ice- cork – drops of oil.

11. Life applications on the
density:
 1- water is not used to put out
petrol fires.
 2- Balloons filled with hydrogen or
helium rise up in air carrying flags
during festivals.
 3- the determination of the change
in the of matter is taken as an
evidence of the purity of matter .

12. 3- Melting point:
 It is the temperature at which a matter
begins to change from a solid state to a
liquid state.
 Note:
different solids have a definite melting
point .
some solid have low melting point
such as wax –butter
some solids have high melting point
such as iron –copper.

13. Life applications on melting
process:
 1- In manufacture of alloys
copper-gold to make jewels .
Nickel –chrome to make heating
coils.
 2- In manufacture of cooking
pots
From aluminum – stainless steel
which do not rust.

14. 4- Boiling point
 It is the temperature at which a matter
begins to change from a liquid state to a
gaseous state.
 Note :
Each substances have different boiling point
(water boil at 100 ).
 Life applications :
Separation of the components of petroleum
oil depends on the difference between
them in their boiling points.

15. 5- Hardness:
 Some solid substances
Soft at room
temperature:
Ex: rubber
Need heat
to be soft
and easy
to shaped
Ex: metals
Do not melt
by heating
Ex : coal -
sulphur

16. Life applications :
 1- the screwdrivers are made of steel iron
because it is very hard.
 2- the rods used in building houses
concrete are made of iron not copper.
because the hardness of iron is more
than that of copper.

17. 6- Electric conductivity:
Good conductors of
electricity.
Substances allow
electricity of flow
through.
Ex: acidic solutions
Alkaline solutions
Some salt solution
Metals as iron
Bad conductors of
electricity.
Substances do not
allow electricity
to flow through.
Ex: gases
Sugary solution
solution of
hydrogen chloride
in benzene
Sulphur –
phosphorus.

18. Life applications:
1- electric wires are made of
copper or aluminum and cover
by plastic layer.
2- screwdrivers are made of steel
iron, while their handles are
made of wood or plastic.

19. Thermal conductivity:
 Good
conductors of
heat
 substance that
allow heat to
flow through
 Ex: metals iron
– copper
aluminum.
 Bad conductors
of heat
 Substances
that do not
allow heat to
flow through
 Ex: wood -
plastic

20. Life applications:
 1- cooking pans are made of
aluminum
because it is good conductor of
heat and has high melting point and
easy to transfer heat.
 2- handles of cooking pans are made
of wood or plastic
because wood and plastic are
bad conductors of heat.

21. Chemical properties
 Metals classified according to their
chemical activity into:
Very active
metals
Metals react with
oxygen as soon
as being
exposed to
humid air.
Ex sodium-
potassium
Less active
metals
Metals they are
metals which
react with
oxygen if left in
air for some
days it is rust.
Ex: iron
In active
metals
Metals react
with oxygen
very difficult
Ex: silver-
nickel

22. Give reasons:
1- sodium and potassium are kept under kerosene
surface.
to prevent their reaction with atmospheric oxygen.
2- steel bridges and the holders of light bulbs painted
from time to time
to protect them from rust and corrosion
3- metallic spare parts of cars are covered with
grease.
to protect them from rust and corrosion.
4- washing of cooking pans made of aluminum with a
rough material .
to remove any layer formed on them.

23. Give reasons:
5- silver and gold are used in making
jewels.
because they are chemically poor
active .
6-nickel,gold and silver are used to
cover other substances which rapidly
gain rust.
to protect them from corrosion.