My friend asked this question about ‘static’ when she was having a bad hair day. Static electricity causes lightning, makes a crackly noise when you take off a polyester jumper, and can make your hair stand on end. But where does static come from?
You might remember an earlier post in which I described how everything is made of chemical elements? Well, that wasn’t the whole story – elements are made up of tiny building blocks known as atoms, which are made up of even smaller units called neutrons, protons and electrons.
You can imagine an atom as being shaped like a ball. Neutrons and protons huddle together in the centre (or ‘nucleus’) of the atom. Electrons whizz around outside the nucleus in a haphazard fashion. And it is the movement of electrons that creates static (and electricity).
An atom’s component parts are kept together by electrical charge. Protons are positively charged (+) and electrons are negatively charged (-). Positive and negative charges attract each other, so the electrons stay near the nucleus and don’t go flying off.
Normally, atoms will have an equal number of electrons and protons. This means that all the positives and negatives cancel out and the atom has no charge (we describe it as being ‘neutral’).
But how does this help us to understand what static is?
Static is caused when electrons move between atoms. Some atoms are good at holding on to their electrons, others are not. If atoms lose electrons, this creates a charge imbalance. This short video gives a more detailed explanation of how this happens.
If I brush the hairs on my head really fast with a plastic brush, I can create a build up of electrons. The electrons repel, or push away from, each other and this causes my hairs to stand on end. We call this effect ‘static’. And it looks and feels funny!
You can try this at home, too! And it doesn’t matter if you don’t have long hair to brush – you can use an inflated party balloon and some tissue paper (as shown in this video). Simply rub the balloon on your hair or a jumper and use the static to pick up the paper.