2. What is matter?
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.
: Is the smallest building unit of matterAtom
3. What’s inside an Atom?
Inside any atom there are small, tiny particles
called: electric charges
Electric charges can have:
Positive charges (+)
Negative charges (-)
5. Examples
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. Charges 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
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. 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 & that’s 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. 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
It is a circuit which doesn’t have any gaps; a
complete, unbroken circuit.
16. Open circuit
A circuit with gaps is called: Open circuit &
current will not flow through it.
17. 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.
19. 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.
21. How to use electricity safely?
There are certain materials that can affect the flow
of the electric current.
Some times the current flow is so high, this can
cause dangerous things like: fires
That’s why we use things to slow down the flow of
electric currents.
22. Resistance
-It is the ability to slow down or oppose an
electric current
{When a current flow with a small resistance, a short
circuit can result; short circuits can be dangerous as the
wire heats up & cause a fire}
23. Fuse-1
- It is a devise that helps to prevent short
circuits.
{It has a thin strip of metal in it, the strip has high
resistance, if too much current flow through, it melts, the
circuit opens & the current stops flowing}
- It is used once only.
{As the metal strip melts so it cannot be used again}
24. - It is a switch that protects circuits.
{ When the current is dangerously high, the switch open &
the current doesn't flow}
- It can be reset “used more than once”
Circuit breakers-2
