Locate on the periodic table the transition elements with the following electron configurations. Identify each element.

(a) [Ar] 3d74s2

(b) [Ar] 3d54s1

Video transcript

Alright. Hi, everyone. So this question says, define the transition metals on the periodic table that correspond to these electron configurations, name each metal. So here we have our two electronic configurations and we have four different answer choices, proposing different transition metals for both one and two. So the interesting thing about transition metals is that according to Iupac a transition metal, it is classified as an element with partially filled D sub shells, whether it be as an atom or as a cion. Now, the phrase transition or transition elements comes from both their location and their properties recall that the D block where transition metals are, is in between the S and the P blocks in the periodic table. So not only does the phrase transition in transition element reflect their location, it also reflects how they bridge the properties between elements in the S and P blocks. So with all that being said, right, let's go ahead and start with our first electronic configuration which is krypton followed by five S 24 D two. Now, in this case, the nopal gas core corresponds to that of krypton, which if you recall is a Nopal gas with an atomic number of 36. Now, because the atomic number is 36 krypton has 36 protons inside the nucleus and therefore 36 electrons in its neutral state. So based on the periodic table, the total number of electrons in krypton is indeed going to be 36 because here we're discussing the neutral state. Now, 36 electrons in the krypton core, as well as two electrons from the five S orbital and two more electrons from the four D orbital gives a total number of electrons of 40. So because the total number of electrons in the neutral state, 40 this corresponds to the atomic number of zirconia with a symbol of the art. Now we can confirm this by following along the periodic table, right? Because after krypton, the first row, after that is going to be or the first block, I should say is in fact five S followed by four D. And we can tell because the valence electrons are present in the five S orbital, which means that zirconium is in fact present in period five. And because the sum of electrons from the four D and five S orbitals is four zirconium should belong to group four. So with that being said, let's go ahead and do the same thing. Part two, which is krypton followed by five S 24 D five. Now krypton once again provides 36 electrons and we have two electrons from the five S orbital as well as five electrons from the four D orbital. This gives a total number of 43 and 43 electrons corresponds to the atomic number of technician or PC. And once again, we can confirm this because technetium should be present in period five, given the fact that it has valence electrons in the five S orbital. And because the sum of the electrons in the four D and five S orbitals is seven technetium should belong in group seven, which it in fact does. So there you have it here is our final answer which in this case corresponds to d in the multiple choice, right? Because transition metal one is zirconium and transition metal two is technetium. So with that being said, thank you so very much for watching. And I hope you found this helpful.