ELECTRICKERY Presented by

Have you ever stuck a balloon to the wall after rubbing it on your head? Have you ever stuck a balloon to the wall after rubbing it on your head? Has your jumper ever made crackling noises when you took it off? Has your jumper ever made crackling noises when you took it off? Have you ever got an electric shock off your door knob? Have you ever got an electric shock off your door knob? Have you ever seen lightening? Have you ever seen lightening?

All these things happen because of Static Electricity

What is Static Electricity? Static electricity occurs when there is a build up of electric charge on the surface of a material. Static electricity occurs when there is a build up of electric charge on the surface of a material. It is called static electricity because the charges don’t move or flow like regular electricity It is called static electricity because the charges don’t move or flow like regular electricity

What is charge? Where do these CHARGES come from? Where do these CHARGES come from? Atoms!

The atom Everything we see around us everyday is made of atoms. Everything we see around us everyday is made of atoms. We can’t see individual atoms because they are so small. We can’t see individual atoms because they are so small. In the air in your classroom there are about atoms. In the air in your classroom there are about atoms.

What is inside the atom? The atom is made of 3 sorts of particles. The atom is made of 3 sorts of particles. The electron The proton The neutron

Charge Most things have the same number of electrons and protons in them – this means they have no overall charge. Most things have the same number of electrons and protons in them – this means they have no overall charge. Charges can be MOVED around by friction Charges can be MOVED around by friction

Static Electricity Only electrons can move. Only electrons can move. Protons are “stuck” in the middle of atoms. Protons are “stuck” in the middle of atoms. Materials that have a positive charge are usually things that have “lost” electrons (not gained protons). Materials that have a positive charge are usually things that have “lost” electrons (not gained protons).

Static Electricity Electrostatic charges build up on insulators. Electrostatic charges build up on insulators. A static charge can be positive or negative. A static charge can be positive or negative.

How do charges behave? Like magnets! Like magnets! opposites attract opposites attract likes repel likes repel Put a + charge near a - charge and they will attract each other. Put a + charge near a - charge and they will attract each other. A charged object may even attract a neutral one. A charged object may even attract a neutral one.

Static electricity The material that has got extra electrons is now (-) charged The material that has got extra electrons is now (-) charged The material which has lost electrons is (+) charged. The material which has lost electrons is (+) charged.

D. Electroscope Electroscope Electroscope instrument that detects the presence of STATIC ELECTRICTY instrument that detects the presence of STATIC ELECTRICTY leaves separate when they gain either a (+) or (-) charge leaves separate when they gain either a (+) or (-) charge

Charging by Friction: FRICTION: when two objects are rubbed together For example: clothes in the dryer When two objects are rubbed together, one will GAIN electrons and the other will LOSE electrons. Only the electrons MOVE during the transfer of electric charge.

Charging by Conduction: CONDUCTION: when objects touch and an electric charge is transferred from one object to another. The neutral object will have the SAME charge as the charged object because the charges are being “shared”. For example: when you walk on a carpet and touch a metal doorknob, you will get a spark. You are transferring some of the charge to the doorknob by conduction.

Charging by Conduction

Charging by Induction: INDUCTION: when objects do not touch and an electric charge is transferred from one object to another. The neutral object will have the OPPOSITE charge as the charged object. For example: when your computer or TV screen is turned on, it begins to build a charge. When a neutral particle of dust comes near the screen, it will become attracted and stick to the screen.

Charging by Induction

Lightning

Unit 3 Static Electricity The typical thundercloud contains areas both positively and negatively charged.

Unit 3 Static Electricity Lightning travels from negative to positive areas.

What causes lightning? Lightning is actually just static electricity on a much larger scale. Lightning is actually just static electricity on a much larger scale. The rubbing is caused by air moving around The rubbing is caused by air moving around In thunderclouds bottom is usually negative and top is positive. In thunderclouds bottom is usually negative and top is positive.

Thunder When the lightning flash happens it heats the air to a temperature 5 times hotter than the surface of the sun. When the lightning flash happens it heats the air to a temperature 5 times hotter than the surface of the sun. This causes nearby air to expand and vibrate forming the sound we hear as thunder. This causes nearby air to expand and vibrate forming the sound we hear as thunder.

Interesting facts Lightning bolts can travel at speeds of up to 60,000 miles per second. Lightning bolts can travel at speeds of up to 60,000 miles per second. Every second around 100 bolts of lightning strike the Earth. Every second around 100 bolts of lightning strike the Earth. One lightning bolt has enough electricity to power 200,000 homes. One lightning bolt has enough electricity to power 200,000 homes. You are more likely to be struck by lightning than be eaten by a shark. You are more likely to be struck by lightning than be eaten by a shark.

Some myths Lightning never strikes in the same place twice. Lightning never strikes in the same place twice. False, the Empire State Building is reportedly struck 100 times a year. False, the Empire State Building is reportedly struck 100 times a year. Wearing rubber shoes will protect me in a thunder storm. Wearing rubber shoes will protect me in a thunder storm. False, Lighting is too powerful to be stopped by half an inch of rubber or several hundred feet of rubber for that matter. False, Lighting is too powerful to be stopped by half an inch of rubber or several hundred feet of rubber for that matter.