2. What is matter?
ď Matter is everything around us & it is made up of
very small particles called: Atom
Example:
Our school is made up of many buildings, buildings
are made up of many bricks together, so bricks are
the smallest building unit of our school.
Atom: Is the smallest building unit of matter
3. Whatâs inside an Atom?
ď Inside any atom there are small, tiny particles
called: electric charges
ď Electric charges can have:
Positive charges (+)
Negative charges (-)
5. Examples
ď Rubbing a balloon with a piece of wool cloth, & then
approaching it to another balloon.
{They will attract}
⢠Rubbing two balloons with a piece of wool &
approaching them to each others.
{ They will repel}
6. ďąCharges Add up:
- When two objects touch, charges move from one
object to another.
{Negative charges moves faster than positive
charges}
A built up of charges:
- When something have more one kind of
charges than the other
7. Examples
ďą When a balloon is rubbed with a piece of wool cloth,
negative charges move from the wool to the balloon,
the balloon will have a built up of negative
charge & the wool will have a built up of positive
charge.
9. ďą Charges move:
It is the fast movement of charges
{When you move on a carpet, negative charges rub off the carpet onto
you, your body gets a built up of negative charges , the charges keep
building until you touch something, then they discharge to whatever
you touch & thatâs why we feel a small shock}
Discharge
10. It is the discharge of static electricity during a
storm
{ Inside a storm cloud, ice & water droplets rub against one another, some
pick up positive charges & move to the top of the clouds; while others
pick up negative charges & move to the bottom, when the build up gets
large enough, the charges jump to the ground as lightening}
Lightening
11. Electric current
It is the flow of electric charges
{ To make an electric current, you need a path that
carry it, the path through which the electric current
flow is called: A circuit}
12. The electric circuit
- A circuit should consist of:
Power source Load Connector
Battery Lamp Wires
14. ďą N.B:
- Some circuits have switches that turn the current
electricity on & off.
- The flow of electric charges through a circuit is
called: Current electricity
15. Closed circuit
ďą It is a circuit which doesnât have any gaps; a
complete, unbroken circuit.
16. Open circuit
ďą A circuit with gaps is called: Open circuit &
current will not flow through it.
17. When it comes to the flow of
electric current, all materials
fall into three categories:
â˘insulators
â˘conductors
18. Insulator â
Any material that does not allow
electric current to pass through it
â˘plastic
â˘rubber
â˘glass
â˘cloth
â˘wood
â˘like the protective coating on wires
19. Insulators like plastic
and rubber are used
as a covering for
electric wires.
This makes electric
wires safer to handle
because the insulator
protects you from the
current.
24. A circuit can also be
opened and closed by
touching two wires together.
Open circuit Closed circuit
No current can flow current can flow
25. A circuit can also be closed
by touching those two wires
to a conductor.
ed circuit
current can flow
26. Types of circuits
Series circuit
In a series circuit, the electric
current flows in the same direction
along a single path.
The same current goes through
all the loads.
28. Parallel circuit
In a parallel circuit, the electric current
flows through more than one path; these
different paths are called: Branches.
-The branches of a parallel circuit
divide the electric current among
them.
30. Electromagnets
A metal bar made into a magnet by passing
an electric current through a coil surrounding it.
⢠When the charged particles of an
electric current move through a wire,
it sets up a magnetic field.
⢠The more the current, the stronger
the magnetic field.
⢠When the current is off, the field
goes away.