The easy way to know the electronic structure for the 3d elements is to follow DrBob's rule. The number of electrons in the 3d orbtials for the 3d transition metals is the second number of the atomic number (EXCEPT for Cr and Cu).
For Co, atomic number 27, that means we have 7 electrons in the 3d orbitals. Since there are five such degenerate orbitals; therefore, draw five boxes in a line, put electrons into each box one at a time). When you have used five electrons you will have one electron in each box and the sixth electron MUST pair up with one already there. The second one MUST pair also. Thus we have left three electrons not paired.
the cobalt atom has how many unpaired electrons in its ground state?
2
4
1
0
3
1 answer