Question

Explain anomalous electronic configuration insime of 3d transitions element in ln

Answer 1

Answer:

Cu has an anomalous electron configuration. Cu = 1s2 2s2 2p6 3s2 3p6 4s1 3d10, it does not follow the usual pattern. In this case, the 3d subshell is filled before the 4s, which usually happens in the reverse order (1s2 2s2 2p6 3s2 3p6 4s2 3d9).

My question is, can you tell by an element's position on the periodic table (Group #, Row #, Block, etc.) that it will have an anomalous electron configuration? Do I have to memorize which elements have this property?

I am noting that Cu is in the 1B Group of Transition metals which implies that it has one valence electron, this is consistent with its configuration. will this be true for all cases?

Also: Fe = 1s2 2s2 2p6 3s2 3p6 4s2 3d6 and is a transition metal as well (Group 8). This implies it must have 8 valence electrons. But following the definition of valence electrons (The number of electrons in outermost shell), n=4 is the outermost shell and I get a conundrum. Obviously if I add 4s+3d electrons everything is good.