Static electricity is a stationary electric charge that is built up on a material. A common example of static electricity is the slight electrical shock that we can get when we touch a doorknob during dry weather. The static electricity is formed when we accumulate extra electrons (negatively-charged particles which we rub off carpeting) and they are discharged onto the doorknob.

Producing Static Electricity
Everything is made up of atoms, and atoms are made of tiny particles, some of which are electrically charged. Most atoms are electrically neutral; the positive charges (protons in the nucleus or center of the atom) cancel out the negative charges (electrons that surround the nucleus in clouds). Opposite charges attract one another. Similar charges repel one another.

Sometimes the outer layer (the negatively-charged electrons) of atoms are rubbed off, producing atoms that have a slight positive charge. The object that did the rubbing will accumulate a slight negative charge as it gets extra electrons. During dry weather, these excess charges do not dissipate very easily, and you get static electricity. (During humid weather, the electrons flow through the damp air and the object become electrically neutral.)

Static Electricity Experiments

Try this: Rub a balloon on your hair. This removes some of the electrons from your hair and gives the balloon a slight negative charge. Now put the balloon against a wall. It will stick (if the weather is dry) since the negative charges in the balloon will re-orient the atoms of the wall, and a weak electrical force will hold the balloon in place on the wall.

Try this (for a really bad hair day): Rub a wool (not acrylic) cap on your hair (on a dry day). This removes some of the electrons from your hair, giving each hair a slight positive electrical charge. Like charges repulse one another, so each hair repulses the other hairs. The result is a mad-scientist hair-do.

Lightning
In 1751, Benjamin Franklin experimented with electricity in a thunder storm, using a kite, a key and a Leyden jar (two conductors separated by an insulator; it is a device for storing static electricity). The thunder cloud leaked electrons (negatively-charged particles) down through the kite's silk sting to the key and into the Leyden jar (on the ground). Franklin himself was insulated from the electricity; he was holding the portion of the string attached to the string but not directly to the Leyden jar. When Franklin touched the key, he got a static shock. DO NOT TRY THIS - many people have died trying it. In 1752, Franklin developed the lightning rod.

Which Objects Lose Electrons Readily?
When two materials are rubbed together (like a balloon and your hair), one will lose electrons and one will accumulate them. Physicists have ranked materials by the order in which they lose or gain electrons. This ranking is called the triboelectric series. A small list of some common materials is shown below. When two of these substances are rubbed together, the one that is higher on the list will usually lose electrons (and accumulate a positive charge). The ones on the bottom of the list gain electrons (accumulate a negative charge).

Triboelectric Series
human skin
rabbit fur
glass
human hair
nylon
sheep's wool
silk
aluminum
paper
cotton
wood
amber
Nickel, Copper, Brass, Silver, Gold, Platinum
acetate, rayon
rubber
polyester
PVC (polyvinylchloride plastic)
teflon

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