Electricity Explained

Getting Down To Basics

By Bruce W. Maki

Full understanding of something as technical as Electricity requires a thorough understanding of the fundamentals. We know this isn't fun, but if you missed out on Physics in high school, and you want to safely do electrical work, then you need this. Sorry!

The Atom and Electrons

The Structure of the Atom

Everything around us is made of atoms. The wood, metal and concrete in your house is made of atoms. People are made from atoms, many different types of atoms.

There are more than one hundred different atoms. All atoms have something in common: 1) their components and, 2) their structure, or the way their components are arranged.

All atoms are made of two or three components. All atoms have protons and electrons. Most atoms also have neutrons. Protons and neutrons are tiny particles and they have tiny amounts of mass or weight. Protons and neutrons usually clump together into a little ball know as the nucleus.

The electrons are even tinier than protons and neutrons. Scientists say that a proton weighs about 2000 times as much as an electron. So electrons are the tiniest of the tiny particles.

Electrons have another interesting feature: They move. Electrons are always on the go, spinning around the nucleus. They spin incredibly fast. If somehow you could see a single atom (and nobody ever has, because of the limitations of certain properties of light) you would not even be able to see the electrons because of their fast orbiting. You would see a ball.

The fast spinning electrons make a kind of shell or force field that the other atoms bump up against. And most atoms have several layers of orbiting electrons, just like our sun has many planets orbiting at different distances. The inner layers of fast-orbiting electrons, or shells as scientists call them, are stable. Those electrons like to stay in orbit, buzzing around the nucleus forever if they could. The outermost shell has electrons that are not so dedicated. The outer electrons, the ones closest to the neighboring atoms, can sometimes be coaxed away.

In solid materials the atoms are close together, touching each other. The electrons from one atom may come very close to the outer shell of its neighboring atom. In some materials, like most metals, the electrons orbiting in the outer layer can be easily led astray. These electrons are sometimes called free electrons, because they freely move from one atom to another, always staying in the outer orbit. Most metals have lots of free electrons. If somehow you could attract these electrons, you can make them move. It just so happens that over the past two centuries scientists have discovered many ways to push or pull these electrons and make them do amazing things.

Electricity is basically about making electrons move around, making them go where we want them to go.