 Okay, so let's continue our discussion of classifying substances. So let's try to classify each of these substances written on the board as an atomic element, a molecular element, a molecular compound, or an ionic compound. So probably the first, the easiest ones to find are the ionic compounds. So could you guys help me with those ones? Do you see any ionic ones up here? Yeah, potassium nitrate, remember that's one of those polyatomics we want to remember. That's an ionic compound, bonded to a non-metal polyatomic. Is there another one around an ionic compound? The cobalt 2 chloride, right? Another ionic compound. Okay, so the other three are non-ionic compounds. So if we look at the periodic table, we might find some of these, so if we look at the periodic table, do we find krypton on it? Yes, right? Look at the periodic table. Yeah, it's there, right? And it's in that group 8, right? So it's a noble gas. So we know that those atoms don't bind with any other atoms. So we're going to call this an atomic. Also, we probably see nitrogen on the periodic table. It's also an element, but remember it's a diatomic element. So that means whenever we have nitrogen, it's actually a molecule and two, okay? So it is an element, but we call it in this case a molecular element, okay, because it's diatomic. You have to remember all your diatomics. That's another list of things that you have to remember like your polyatomic ions. So all we have left here is sulfur dioxide. Of course, it's not an ionic compound, so it must be a molecular compound, okay? And you might say, wait, I thought that was a covalent compound. Covalent compounds are molecular compounds, okay? So when you see a nonmetal bonded to a nonmetal, covalent or molecular, okay? Any questions on this example? Hopefully it makes sense.