Ask Science talks about electricity: what it is, how it works, and why you need it to turn on a light bulb.
When I was a kid, one of my favorite movies was Breakin’ 2: Electric Boogaloo.
The movie had nothing to do with electricity, and not very much to do with boogaloo either. While the movie didn’t do much for my horrible dance skills, it did give me occasional thoughts about how cool it would be to open up a community center for teens.
You might be wondering what this has to do with science. Is this a science of dance episode? Unfortunately, it’s just a rather paltry attempt to use humor in introducing the subject of this week’s episode: electricity.
What Is Electricity?
What most people call “electricity” is what scientists call “electric current.” If the first thing that comes to your mind when you hear the word current is a swiftly flowing river or undersea stream of water pushing boats along their course, you’re not far off. Electric current is a stream of charged particles.
There are a few different types of charged particle carriers, but usually when we talk about electricity, we’re talking about electrons. If you remember my episode about atoms, you’ll remember that electrons are the little negatively charged particles that float around the nucleus of atoms.
See also: What Is Static Electricity?
Despite what you may have learned by watching Jimmy Neutron, electrons don’t orbit around atomic nuclei like planets in a miniature solar system. Instead electrons to spend most of their time in specific areas around the nucleus called atomic orbitals. These orbitals have various shapes, depending on how many electrons an atom has, and a couple of other factors.
These atomic orbitals are arranged in layers around the nucleus. For the purposes of electricity, the only electrons we really care about are those in the outer shell, which are sometimes called the valence electrons.
When electrical current flows, what’s really happening is that these valence electrons are moving from atom to atom.
Imagine for a moment that you’ve got a length of wire that is one atom thick in diameter. If you push an electron into one end of that wire (say from a battery), it’s going to try and jump into the valence shell of the first atom it encounters. When this new electron comes in, it pushes one of the valence electrons out of the atom, which moves into the next atom, and the process continues all the way down the length of the wire.
See also: Why Doesn't Static Electricity Kill You?