Static Electricity – Hair-Raising Science
During the winter months, static electricity can build up and cause a shock when we touch a piece of metal or someone else. You can actually feel, see and hear the spark jump from your body or see it when you rub two cotton blankets together. But what happens to cause that shock and zap and why is it worse in the winter?
First you have to understand atoms, the things that make up all matter. Do you remember high school physics? The nucleus of an atom has neutrons and protons (positive). The shell is made up of electrons (negative). When the number of electrons and protons are even, the atom is neutrally charged. If there are more electrons, the atom is negatively charged. More protons, it’s positively charged.
Some atoms want to keep their electrons, while others will give them up when they come in contact with another material.
When two materials come in contact with each other, one material will take some of the electrons from the other. When the materials are separated, a charge imbalance happens. The material with more electrons is negatively charged and the one with more protons is positively charged. This charge imbalance is where static electricity is created. Shuffling your stocking feet across the carpet picks up the electrons. When you touch the light switch or another person, you transfer those electrons in a static charge. The charge you feel is the flow of imbalanced electrons.
The reason why you have more of a static electricity problem in the winter is lack of humidity. Moisture covers the material and allows for a path of electron flow. A low-resistance path allows the electrons to stay together and not cause a charge imbalance. A dry material can allow electrons to build up and create an imbalance. That’s why only certain materials conduct static electricity and others do not. Carpet, dry skin, hair, rubber, nylon, lead and cat fur are all great electron sharing materials.
A Van de Graaff generator creates static electricity. Cranking the handle on the generator moves a roller and turns a belt. A roller begins to build a negative charge and collects electrons. The electrons move up the belt that acts like an elevator. The electrons collect on the outside of the silver ball on the generator and are easily transferred to anything that comes in contact, especially something like skin that will conduct it. Leave your hand on the silver ball and the electrons move through your body and onto your hair. Dry, straight hair is best to capture the electrons. They move on the hair looking for a transfer material to rebalance again. Once the shock or electrons are transferred, the hair sits back down.
Here are some experiments on Static Electricity: