Matter is anything that has mass and occupies space. It can be distinguished by physical properties like color, density, melting point, boiling point, hardness, and conductivity, or by chemical properties like reactivity. Density is a physical property defined as mass per unit volume. It allows materials to be differentiated as some materials sink in water while others float, and is important in applications like balloons and determining purity. Melting and boiling points are temperatures at which matter changes state, and vary between materials. Hardness, conductivity, and other properties influence what materials are suitable for different uses like cookware or wires. Chemical reactivity ranges from very reactive metals like sodium to less reactive like iron to inactive like silver.

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.