So now that we've introduced acids in our last lesson video, in this video we're going to introduce bases. Bases are pretty much the complete opposite of acids. That's because instead of increasing the concentration of hydrogen ions, bases are any chemical that decreases a solution's concentration of hydrogen ions. A classic example of a base is Sodium Hydroxide, or NaOH. If we take a look at our image down below at the addition of Sodium Hydroxide or NaOH to water, then we'll be able to see an example of a base.

Notice over here on the far left, we're showing you 3 molecules of sodium hydroxide or NaOH, 1, 2, and 3. When each of these sodium hydroxide molecules is added to water, they will actually split into 2 substances: they will split into sodium ions and hydroxide ions. You can see that when we add these 3 sodium hydroxide molecules to water, the sodium hydroxide molecules are going to split into sodium ions and hydroxide ions. You'll notice that even in some pure water over here that there's going to be a little bit of hydrogen ions floating around, and so you can see that we start with 3 hydrogen ions.

It's important to note that each of these hydrogen ions that we see here will actually interact with the hydroxide ions. When the hydrogen ions interact with the hydroxide ions, it creates water molecules. You can see that the hydrogen ions are now being decreased. Over here in the last beaker, because once again all of the hydroxide ions interact with the hydrogen ions to form water molecules, notice that in this final beaker over here on the right, the concentration of hydrogen ions has indeed been decreased. Unlike acids, which result in increased hydrogen ion concentration, bases result in decreased hydrogen ion concentration just as we see here.

This concludes our introduction to bases, and we'll be able to get some practice as we move forward in our course. So I'll see you all in our next video.