 Let's do this problem. It'll be the last problem we do before lunch. So which would be a more polar bond? HF bond or HCl bond. So remember that this question has to do with the electronegativity difference. So you're going to have to look at the electronegativity table. So if you look at your electronegativity table, which you'll see that the electronegativities of these elements are H is 2.1 F is 4.0 and these are in units of Debye's capital D and Cl is I believe 3.1 3.4 Okay on R electronegativity. So what are you going to do? Well, you just figure out what the difference is. So the more electronegative minus the less electronegative, so 4.0, so we can say let's do it formally. So we'll say the change. So this little triangle means change electronegativity. So the change in electronegativity between these two is going to be 4.0 Debye's minus 2.1 Debye's. So when you do that, of course, it's going to be 1.9 Debye's and that's for the HF. And let's do the same thing, change in the electronegativity for the HCl bond 2.1. It's more polar. Well, this one's going to be more polar. Why? Because the difference in polarity or the difference in electronegativity is bigger. It's out of comparison.