Electricity is a form of energy made of charged particles . The electricity supply is made of negatively charged electrons . Electricity can be static ( remaining still ) or it can flow as a current .
You probably already know that things are made of atoms . Here ’ s a Rutherford- Bohr diagram of a copper atom . This is not exactly how an atom looks , but it helps us to understand the structure more easily . All atoms look a bit like this , but with more or fewer protons , electrons and neutrons .
Imagine a copper wire , just like the one inside a plug . It ’ s made of lots of copper atoms , each with an easily removed outer electron . If a copper electron gets free , it will attach to a neighbouring atom , giving that atom extra negative charge . This is unbalanced , so the atom ejects an electron to give a free electron again . The process continues as a free electron moves from one copper atom to another along the piece of copper wire . This gives us an electric current . This is a very simple explanation , you could do some more research if you ’ d like to know more .
REMEMBER that electricity is very dangerous , and not to be messed with .
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Copper has a central nucleus of 35 neutrons ( neutrally charged ) and 29 protons ( positively charged ). Keeping the atom in balance are 29 negatively charged electrons that orbit around the outside . Some are closer to the nucleus than others and their spacing is shown by the lines in the diagram . The protons attract the electrons and an equal number of each ( in this case , 29 ) means the atom has a balanced charge . The single electron furthest away from the nucleus has the weakest pull on it . It can be removed to give a free electron .
Atoms with easily-removed outer electrons are good conductors , because you can get a current to move through them easily . The best conductors include copper and the other metals used in electronic equipment . It is more difficult to get a flow of current if the electrons are not easily removed . This is what makes glass , rubber , plastic and air into poor conductors . In fact , they are so bad at conducting , we call them insulators .
Illustration by Joe Todd-Stanton . Words by Dr Sarah Bearchell