One of the elements shown on the following periodic table has an anomalous ground-state electron configuration. Which is it—red, blue, or green—and why?

Video transcript

Hello everyone today. We are being given the following problem. Consider the following illustration of the periodic table identify which among the highlighted element has an anomalous ground state electron configuration justify your answer. So that word anomalous. Sounds familiar to anomaly. Which pretty much just means a typical. So which one of these highlighted elements deviates from the standard electron configuration. So let's go down the list. So you start with a A. Has the atomic number Of 17 which corresponds to chlorine. And so that means that chlorine has 17 electrons. So it's condensed electron configuration. If we were to draw it out, we would look for the noble gas that is just before chlorine. So it would be in this space here and that would be neon followed by our s orbital. So we're gonna go to the next row, which would be the third row. So we're gonna have three, we start with s we're filling in those two electrons. And then we moved to the p orbital 12345 A is in the fifth position. So that's going to be three P five. And so this is going to be not an exception. So this follows the standard rules. We then move to be And so B if we compare B to a periodic table, that's going to have an atomic number of 47. And so that's going to correspond with a G. Or gold. And that has 47 electrons. If we look at the condensed formula for B or gold, we're gonna look for the noble gas. That is just before that. So in this region here and then it's going to be krypton Kr. Since we are in since B is in the fifth row or the fifth period, we're going to have five s to since we're filling in those and they were going to have four D. Since we're entering the transition metals 1234567894 D nine. However, something special about do orbital's is that sometimes they differ. And so we can note that D orbital's prefer either completely failed orbital's or half filled orbital's. So with our orbital being 49, it is neither. And so essentially we're going to have an electron that has to come from somewhere to compensate for this. So this is going to turn into our krypton And this is going to be five S 1 four D 10. And so this sure does not look like the normal rule. And so our answer is going to be be and so we said that that is because the expected electron configuration is the one we drew first with our krypton five S one S 2 49. However, there is a rule that or the trend that D orbital's tend to want to be completely filled or half filled and so we're going to take an electron from that five s orbital and transferred over to the four D orbital giving us our new configuration here, which definitely deviates from the norm. And so with that we have answered our question overall, I hope this helped, and until next time.