 OK, let's start today with this problem. So based on only the information available on the periodic table, so I've drawn what you might see on the periodic table or at least one item, in this case, flooring. What is the elemental symbol of flooring? So remember, the elemental symbol, of course, is the symbol and letters that defines the actual atom that you're talking about, so you don't have to write the name out. So it's the short-hand way of writing the name. And of course, in this case, the atomic symbol is there, capital F for flooring, or the elemental symbol, whatever you want to say. The atomic number of flooring is this number here, nine. So if you look at the periodic table, flooring is the ninth element on the periodic table. So in this case, well, that and it's got nine protons, which we'll talk about in a second. But since it's the ninth one on the periodic table, that's its atomic number. The atomic weight of flooring is what you find on the periodic table. And that's the weighted average of all the isotopes of flooring or of any element is the atomic weight. That's this number down here. And we'll talk more about what isotopes are and how to get that weighted average. How they got that number on the periodic table. But that's essentially, if you want to think about it, is the average mass of all of the flooring atoms in the universe. So most of them are flooring 19, but some of them are other flooring isotopes. And again, we'll talk about those in a second. What's the next one? So how many protons does flooring contain? Like I said, it's the same number as the atomic number. So the atomic number tells you the number of protons it contains. So it's nine, of course. How many electrons does flooring contain? Well, the neutral atom flooring will contain as many protons as it does electrons. So of course, that's going to be nine as well. And then is flooring a metal, metalloid, or non-metal? Well, you need the whole periodic table to figure out that one. But if you look at it, remember the staircase defines where the metalloids are. And to the left of that staircase is the metals. And to the right is the non-metals. And if you'll notice, flooring is on the right of that. It's one of the halogens, if you remember that. So it's a non-metal. And what group is flooring in? Well, it's in either 7A or 17. And you can say either one of those is fine. So we'll do one more of these. And that should give you a pretty good idea of what's going on here.