So remember we said that organic chemistry is the chemistry of life. So we're not going to see heavy metals involved in organic reactions for the most part or in biological systems. Because of this, the most important rows of the periodic table are rows 12. And sometimes on occasion, you might see row 3 being involved. A vast majority of the reactions will deal with the elements in these three rows. Now, of course, like plants, you wouldn't see a plant composed of atoms of lead, or platinum, or mercury. We will come into contact with reactions, of course, dealing with oxygen and nitrogen and sulfur, things like that.

Now just a crash course in reading this periodic table. We can see that the periodic table has about 118 elements. Now, I haven't filled out everything in terms of this graph, but remember, this bottom row here, it has been completely filled in with conventional names for the elements that are here, here, and here. But again, we're not really concerned with that; we're really focusing on the first three rows.

Now when we talk about rows, remember another name for a row is a period. So, we have row 1, which contains hydrogen and helium, row 2 or period 2, which is lithium, lithium all the way to neon. Row 3 or period 3 is sodium all the way to argon. Besides rows or periods, we have groups. So, our groups represent our columns, or the fancy term families. Now, we'll tend to say groups or columns when we're talking about each one of these groups. So, group 1A here is hydrogen all the way down to Fr, group 2A all the way to group 8A over here.

Now we're not concerning ourselves with the elements found here in the pit. These are your transition metals. They themselves, they're not group A elements, they're transition metals. They're kind of weird. This would actually be, 1B here and 2B here, and then it would crisp it would come back over here as 3B. So transition metals are a bit weird. Just realize that in organic chemistry, we only care mainly about the first three rows or periods, because those are our nonmetal, for the most part, elements. They'll be involved in a lot of reactions you're going to see throughout this course. Okay? So just keep that in mind. Remember, groups are your columns, periods are your rows. We care mainly about the first three rows of the periodic table.