Static Electricity

Static Electricity In this topic you will learn:

Keywords

Static Electricity Everything in the world is made up of atoms. Each atom has smaller parts in it. One of those parts is called electrons. Electrons can move from atom to atom. When an electron moves to a different atom, it causes another electron to have to move. When electrons move quickly from one atom to another is it called Electricity!

Static Electricity Inside an atom, electrons have a negative charge and protons have a positive charge. These particles attract each other. A charge is a measure of the extra positive or negative particles that an object has.

Static Electricity Static electricity is the charge that stays on an object. Unlike charges attract each other, and like charges repel each other.

STATIC MEANS STANDING STILL Static Electricity STATIC MEANS STANDING STILL

TWO kinds of electric energy Static Electricity TWO kinds of electric energy Static Electricity Current Electricity

Static Electricity To understand static electricity we need to understand the structure of atoms Atoms are made of 3 particles Protons which carry positive charge. Neutrons which carry no charge Electrons which carry negative charge. } Make up the nucleus } Orbit the nucleus

Static Electricity Nucleus Protons Neutrons

Static Electricity NUCLEUS + ELECTRONS = ATOM

Static Electricity Neutral Normally the number of PROTONS = the number of ELECTRONS Neutral

Static Electricity Positive Sometimes an atom loses an electron leaving the Atom with excess positive charge. Missing Electron Positive

Static Electricity Negative Sometimes an atom gains an electron leaving the Atom with excess negative charge. Negative Extra Electron

Different charges attract Static Electricity Different charges attract Same charges repel

Static Electricity Like charges repel and unlike charges attract

Static Electricity CHARGING a balloon

Static Electricity Why does a balloon stick to the wall?

Static Electricity Why does your hair do this?

Static Electricity Because all the + charges repel

Static Electricity Using a Van de Graaff generator to build up a static charge.

Static Electricity Glass + Silk Cotton + Plastic Hard rubber + Fur

Static Electricity Useful effects of static electricity Remove soot from chimneys stopping pollution In photocopiers when the toner is attracted to the charged rotating drum. In spray painting droplets of paint are charged and attracted to the surface to be painted. When spraying pesticides droplets are attracted to the leaves.

Static Electricity Nuisance effects of static electricity Sometimes you get a small electric shock when you touch a car door after a long journey. When you brush your hair the hair refuses to stay flat due static repulsion. Plastics, windscreens, TV screens attract dust due to static electricity.

Static Electricity Dangerous effects of static electricity When dealing with inflammable liquids or gases one spark may cause an explosion, e.g aeroplanes pick a large static charge cutting though the air and clouds so this must be removed before refuelling. Great care must be taken on oil tankers to avoid sparks. The crew wear anti-static clothes and shoes. Strokes of lightning can cause alot of damage to buildings etc. if the charge is released to earth it called fork lightning and if the charge is released to a nearby cloud it is called sheet lightning.

Static Electricity Conductors and Insulators Static electricity is due to the fact that charges on some materials cannot move. For other materials the charge can move. Insulators are substances which do not normally allow charge to flow. Conductors are substances which allow charge to flow through them

Static Electricity Earthing If a insulator with a large static charge is touched by you the charge escapes through giving you an electric shock and the charge through you to the earth. An escape route though a conductor to the earth for electricity is called an earth connection. An object with an earth connection cannot built up a large static charge.

Static Electricity Examples of Earthing In a large heated building walking along the carpet may result in a static charge building up on you. When you touch a metal object e.g a radiator or door handle you get an electric shock as electricity is travelling though you to the earth. A lightning conductor is metal spike ón the top of a high building connected to a metal plate buried in the ground by a copper strip. If lightning strikes the building it travels though the lightning conductor harmlessly to the earth and so preventing damage to the building from lightning. The lightning conductor was invented by Benjamin Franklin.