So remember exceptions start with chromium. So let's look at chromium if we're to determine its electron configuration. Initially, we would see that it would look like are gone for us to three d four. Now here. What do we have here? We have three D with four electrons within it. But remember earlier we said that s N d sub shells or sub levels have this urge to try to be half filled or totally filled. Now we're gonna say an s orbital electron can be promoted to create half filled orbital's with D four electrons. So what we're saying here is if you're doing the electron configuration of chromium, you're gonna end with a D four. That's a key to tell you that O d four. We have only four electrons within these d orbital's. But if I could somehow get one more electron in there, those deorbit will be half filled. So what's gonna happen here is we're gonna take one electron from the forests and donated over here, so our three d four is going to become a D five and our for us to just gave up on electrons. It becomes for us one. So it now looks like this. This would be the correct electron configuration of chromium. So again, remember, chromium has this type of exception, and the driving force is trying to get a half filled set of d orbital's. Okay, so here we're not gonna land. We're not going to stay as D four when it's neutral. It's gonna become a D five. Now that we've seen this with the first column, let's see what happens with the second column. So click on the next video and let's see what happens with them.