Hi. I'm Robin Higgins and this is "What Does "HCl" Stand for in Science?" Okay. So, HCl is a chemical formula and, if you look on the periodic table, you'll see that it divides into two different elements, hydrogen and chlorine. And, if you check that periodic table, you'll see that hydrogen has one hydrogen has one electron and chlorine has seven. So, HCl forms an ionic bond because this hydrogen completely gives this chlorine its electron. And so, this guy goes over there and then what you get are two different ions so you get positively-charged hydrogen and negatively-charged chlorine. And so, the way that you get these charges to actually happen is to dissolve. So, if you put HCl in water, what you'll get is a bunch of positively-charged hydrogens and there are these chlorines in there too. Okay. So, we've - now, we've broken down what it is, but its name is hydrochloric acid. It's actually a very strong acid. If you spill, even a drop on your hand, it's going to feel like a bee stung you. It's going to be really unpleasant. And so, when we measure acids, if you've ever heard of measuring the pH of something, what that is is actually measuring how many of these free hydrogens are there. And so, with hydrochloric acid, we know that we have a lot because every single one is going to disassociate and give us a free hydrogen. So, HCl, hydrochloric acid, very, very low pH, disassociates into positively-charged hydrogens and negatively-charged chlorines. I'm Robin Higgins and this is "What Does "HCl" Stand for in Chemistry?"