So at this point we know that the mole represents the amount of a substance. But if we were to take a look at its formal definition, we'd say that the mole is the mass of substance containing the same number of units as Adams in 12 g of carbon 12 isotope. And we're going to say here that the mole also acts as a way of connecting together different terms. These terms include atoms, ions, molecules and formula units. Some of these terms we've seen before, some of them are new, so let's investigate each of them. And Adam, Remember, we've used the term Adam interchangeably with neutral elements. So we're going to stay here in Adam is a single element with no charge. Ion and ion is also a single element, but it possesses a charge. That charge could be either positive or negative. Ah, molecule, we're gonna find as a compound with two or mawr non metals together. Those non metals could be the same, or they could be different from one another and then finally, formally unit formally unit is just a general term for a compound composed of a metal and nonmetal. So as we delve deeper into the mold concept, just realized that the mole kind acts as a bridge that connects together these different ideas when it comes to the elements and how they arranged with one another.