MicroBooster Video Transcript

This is a transcript of the video on the Educator Features page and Student Features page.

In this lesson we'll begin looking at chemical bonding, which is how atoms join together.

Specifically, we will focus on the parts of an atom that interact to allow bonding to occur, the valence electrons.

To begin let's quickly review atomic structure.

Let's say it's a summer night and you are home waiting for a pizza or a friend to arrive.

You turn on the outside light and almost as soon as you do you know what's going to happen, right?

Bugs are drawn to the light and start hanging around it, but they don't just stop and stay in one place, do they?

They swarm around the light, flying, or orbiting, around it, kind of forming a bug cloud around the light.

You can think of the light in the center of the cloud as representing the nucleus of an atom.

Recall from basic atomic structure that the nucleus is the center part of an atom, where protons and neutrons hang out.

That leaves the electrons.

Electrons always orbit around the nucleus, staying in constant motion and forming an electron cloud around the nucleus, much like the bug cloud that formed around the light in our demonstration.

Here we see one atom, represented by the light as the nucleus and the bug cloud as the electron cloud.

But chemical bonding only occurs when two or more atoms interact with each other.

To see how atoms interact to form a chemical bond, we need another atom, so let's add another light and wait for more bugs, or should I say electrons, to show up.

Our picture is getting rather crowded though, so let's get rid of the stuff that doesn't matter for chemical bonding.

We can even get rid of the lights themselves, representing the nuclei of the atoms, because neither the protons nor the neutrons participate in chemical bonding.

We just need a look at the electron clouds.

Within these clouds, and again rather like the bugs around a light, some of the electrons orbit very close to the nucleus while others stay a little farther out.

These different areas represent electron shells, or orbitals.

In this image, each atom has two orbitals.

Looking at this image, what part of the atoms do you think are most likely to interact if the atoms move close together?