Now when looking at exceptions to the electron configurations, we're going to say starting from chromium, which is CR. As the atomic number Z increases, exceptions to electron configurations can be observed. A memory tool here we can have is that chromium has an atomic number of 24. So think about that two and four.

We're going to say that the exceptions happen with these two elements and with these four elements, so two and four. We're going to say here we're going to start out with chromium. We know that's where it starts and we're going to skip the next 4 columns. So we start out with chromium and you skip next four, so skip manganese, skip iron, skip cobalt, skip nickel, and then you land on copper where the next group of exceptions can exist.

So just remember, these are the six major types of elements where we're going to see exceptions to the electron configuration. So keep this in mind when we're looking at their electron configurations. Now that we've know that these are the six that we have to deal with, let's see how these exceptions arise. So click on the next video and let's see what happens.