In this article we learn about the science behind static electricity.In Static Electricity Experiments we investigate static electricity further.Rubbing a balloon on your head and sticking it to a wall is an example of static electricity.
So is walking across a carpeted floor and then touching a metal door handle.You receive an electric shock in your hand.
Another example is pulling your washing out of a tumble dryer and observing how some of your dry washing sticks together.
Static electricity occurs after you turn off the TV and hearing a ‘crackling’ sound as you touch the screen.
Going down a plastic slide and your hair sticks up!
Bending water after combing your hair!
A comb picking up bits of paper after combing your hair!
A spectacular display of lightning- another example of static electricity!
To understand the science behind static electricity we must first learn a little bit about the structure of ‘atoms’.
Everything in the universe is made of very small particles of matter called ‘atoms’.
Atoms join together and are so small that in the width of one human hair or in a single grain of sand there are more than 1 000 000 atoms!
Each atom has a nucleus (or center) composed of sub atomic particles called ‘protons’, all of which have a positive electrical charge. Since all protons have a positive electrical charge you might think that they would repel each other, but this is not the case.
Neutrons, which also form part of an atomic nucleus, help ‘glue’ the protons together preventing the protons from repelling each other.
Neutrons have no electrical charge and can best be described as ‘electrically neutral’.
In the empty spaces orbiting each atom are negatively charged particles called electrons. These negatively charged particles orbit the atomic nucleus.
If an atom contains equal numbers of protons and electrons, then that atom can be described as being ‘electrically neutral.’
In an electrically neutral atom each positively charged proton cancels out each negatively charged electron. The atom in the animation below is ‘electrically neutral’ since there are three protons in the nucleus and three electrons orbiting the nucleus.
Electrons have a very weak attachment to the atomic nuclei that they orbit, and can easily be ‘persuaded’ to leave the orbit of one atomic nucleus and attach themselves to the orbit of another atomic nucleus.
In contrast the nucleus of an atom remains stable and does not alter in any way. The protons and electrons remain fixed in their nuclei.
When you rub your hair with a balloon you cause friction. Friction is a force that ‘excites’ atoms and gives them energy. What happens when atoms gain extra energy? You can see the results in the images below, where you have to ‘spot the difference’!
The diagram below shows an atom from one of your strands of hair before friction is created when you rub your hair with a balloon.
This diagram shows an atom from one of your strands of hair after rubbing your hair with the balloon.
The atoms in your hair now have a positive electrical charge because each atom contains fewer electrons than protons.
This is an atom from the balloon after you have rubbed the balloon with your hair.
The atoms of the balloon have a negative electrical charge because each atom contains more electrons than protons. Every atom of the balloon which came into contact with your hair has gained extra electrons.
So there is now an imbalance of electrical charges within the surface of two different ‘materials’. This imbalance of electrical charges (positively charged atoms in your hair and negatively charged atoms in the balloon) causes opposite electrical charges to attract.
So what do you think happens next?!!
How small are atoms? Watch ‘Ted Talks’ (up to 3:20) and be amazed!