 Okay, so we're talking about reaction spontaneity right now. And we're talking about the interplay between delta S and delta H, okay? So we know that it's good, right? What are the good things? Make a reaction happen. What have we talked about? Delta H has to be what? Negative. Negative. And delta S has to be positive. And the bad things? Delta H is positive. And delta S is negative, okay? So remember, delta H and delta S, that's going to, the addition of those two things, okay, are going to tell you whether a reaction is going to occur or not, okay? So if a reaction occurs, we call it spontaneous, okay? So in the first set, it said the process will always be spontaneous. You know it will always be spontaneous if you've got what? Delta H is negative, very good, and the S is positive. Does that make sense? Because those are the good things. If they're both there, that's what's going, it's going to happen. It's going to be spontaneous. Okay, so our next example says, well, this one absorbs energy. So what does that mean in relation to delta H, delta S? Delta H is positive. So if we want this reaction to be spontaneous, what must also occur? Delta S has to be positive, but it's got to be more positive than whatever this delta H is, negative, right, or supposed to be negative to make that reaction occur. So this has to be more positive than this is positive. What about a process that causes an entropy decrease? What does that mean? Delta S is negative. So when will that process be spontaneous? When delta H is negative, but, what, it's got to be more negative than the delta S. Is everybody cool with that? So spontaneous things, or spontaneous things will happen in these sorts of situations, okay? This situation and this situation don't always occur though, okay? They're not always spontaneous. This situation always is spontaneous. In these situations where they're both positive or they're both negative, you're going to have to compare those numbers and we'll do problems about this. How about, can anybody tell me in a situation where the reaction is never going to occur? When you've got the two bads, when we say the reaction is non-spontaneous, non-spontaneous when delta H is plus and delta S is minus. Why? Why does that make sense, right? Because the reaction is doing what? It's absorbing energy, which is already a bad process, and it's becoming more organized, which really is a bad process, right? So it's not going to occur. So is everybody okay with that? Are there any questions about this in particular? Can I kill this video? Okay. Good job, guys.