Electrostatics - Shockingly Brilliant!
Objects can have a positive, negative or neutral charge depends on their atoms state. An object that gains electrons becomes negatively charged and a substance that loses an electron becomes positively charged. These charged objects will then attract or repel each other if the come into range of the electromagnetic forces of the two objects overlapping. If the charges are the same then they will repel, if the charges are opposite then they will attract and if an object with charge comes into contact with an object without charge they will attract.
In an atom there are two key parts;
-The positively charged nucleus
-The negatively charged electrons
In an unchanged atom, the positive and negative charges cancel each other out because there is an equal amount of positive and negative charges. When we talk about an object being charged this means that the object either has more electrons in its atoms than protons or fewer electrons than protons. An object can become positively or negatively charged by exchanging electrons with another object.
You can get an electrostatic shock if you are electrically charged and you touch another object which is earthed. Being earthed means that you have a neutral charge and, as we discussed above, means that the charges attract and electrons are transferred from the charged object to the earthed object through electric current(shock).
Static electricity isn't just a phenomenon that occurs by getting shocked by another person, it also happens on a much bigger scale. Static electricity builds up in clouds due to friction mostly occurring in cloudy or stormy weather. This causes a huge spark to form between the ground and the clouds. This is known as lightning and it is just as simple as the electric shock, where a charged object e.g. the clouds wants to transfer electrons to a grounded source e.g. the ground. Static is highly dangerous when there is inflammable gases or vapours that a could be set alight by a spark of electrostatic. Also, an electric shock could be fatal or damaging if the charge is high enough, this is why there are big safety warnings near power lines and electric fences because a shock could cause serious burning or stop your heart. An electrostatic shock could stop your heart because your heart is controlled by electric signals sent through neutrons and when that connection is broken the heart will literally stop beating.
However, the chance of receiving an electric shock is reduced if;
-An object that might become charged is connected to the Earth by a wire that any charge can immediately flow down. Your washing machine or electric oven has this to stop fire risks and fatal electric shocks.
-If you stand on an insulating mat or if you have shoes with insulating soles it stops charge flowing through them to the ground. These are usually made of rubber or other good insulators. This stops the electron flow because it stops the electrons reaching the ground to cause the charge because it doesn't allow electrons through it easily.
Uses of electrostatics
The power of electrostatics has been harnessed for use in everyday life. Photocopiers and laser printers use electrostatic to print duplicates of papers. It does this by placing the image on a positively charged copying plate where the light that falls in the spaces of the images leaks away from the charge. Then a negatively charged black toner is attracted to the remaining positive areas and the picture is copied. Then the paper is placed of a copying plate and heated to make the toner stick. Then you are left with a duplicate of the image.
Also, Defibrillators use electrostatic to restart the heart. Two paddles are charged from a high voltage power supply. The charge then passes through the patient's body towards the ground through the heart. This will hopefully restart the heart as it reconnects the lost electric nerve connection that keep the heart beating.