How Does Electricity Work?

Everyday Einstein talks about electricity: what it is, how it works, and why you need it to turn on a light bulb. 

Lee Falin, PhD,
March 14, 2014
Episode #092

Page 2 of 2

You probably know that conductors conduct electricity, while insulators don’t. What you might not know is what makes the difference between an insulator and a conductor, is how their valence electrons behave.

In most insulators, the nucleus of the atom excerts a strong enough pull on the valence electrons that it is hard for them to get pushed out of position. Since the electrons aren’t moving, we don’t get any electrical current.

There are a few different factors that can determine whether something is an insulator or a conductor. One of the reasons that the valence electrons of atoms like copper and silver can flow so freely from atom to atom is that they have so many electrons in their inner shells, that the valence electrons are shielded from the pull of the nucleus. This allows the valence electrons to hop willy nilly from atom to atom whenever a new electron comes to push them aside.

Let There Be Light

Electrons moving around wires are great, but what if we want to use electricity to do something useful, like turn on the light? Well once again, it’s the electrons that are the stars of the show here.

In the case of incandescent light bulbs, as electrons move into the filament, they excite the atoms in the filament causing them to vibrate. This vibration causes some electrons to get transferred to a higher energy shell, but this change is only temporary. After a short time, the electron falls back to its previous level, releasing its extra energy in the form of a photon, or particle of light.


So now you know more about electricity, what it does and how it does it. You also know what makes some things conductors versus insulators.


Electricity image, Filter Forge at Flickr. CC BY 2.0. Atom image courtesy of Shutterstock.


Related Tips

You May Also Like...