Matter is made up of particles called atoms

• Inside the atom are even tinier particles.• Some of them have positive electrical charge (+)• Others have a negative electrical charge (-)

The (+) and (-) charges are like the north pole and south pole

of a magnet.

North pole and north pole = repel

South pole and south pole = repel

Like poles repel ( go away ) from each other.

The (+) and (-) charges are like the north pole and south pole

of a magnet.

North pole and south pole = attract

Opposite poles ( attract ) pull each other.

( + ) and ( + ) = repel

( - ) and ( - ) = repel

( + ) and ( - ) = attract

( - ) and ( + ) = attract

Count the number of (+) and (-) charges in an atom.

Most matter has the same number of (+) and (-) charges.

This means that the atom is neutral

Which charge do you think it moves easily out of the atom?

(-) charge moves easily out of the atom.

When does the (-) charge leaves the atom?

When two objects touch, negative electric charge can move from one object to another.

Rub a balloon with wool cloth.

What do you think?The cloth or the balloon (-) charges moves

more easily than the other?

Rub a balloon with wool cloth.

The balloon is buildup of (-) charges.the wool is buildup of (+) charges

Has more of one kind of charge than the other.

Static electricity

The buildup of electrical charges on an object.

What happens when you hold the negatively charged balloon near a wall?

The (-) charge of the balloon repels the (-) charge of the wall and attracts the (+) charge of the wall.

This pull makes the balloon stick to the wall.

How have you experienced static electricity?

1-When we walk across a carpet, negative charges from the carpet goes onto you.

2-Your body is now buildup of negative charges.

The negative charges are kept on our body until we touch something and then :

How have you experienced static electricity?

The movement of the charges is called discharge.

The shock that you feel is the fast movement of negative charges from your body to

another object.

How have you experienced static electricity?

Not all discharge of static electricity result in small shocks…..

lightning

Lightning is a discharge of static electricity during a storm.

Storm cloud

Ice and water droplets rub against each other

- - - - - - - - - - - - - -

Storm cloud

Those who got the negative charges moves to the bottom of the cloud

+ + + + + + + + + + + + + + +

If the build up of negative charges gets large enough, the charges jump to the ground as

lightning

Experiments

• Rub a balloon with your hair and stick it to the wall.

• Rub a ruler with your hair and stick it to a paper.

How have you experienced static electricity?