Why is the first ionization energy of magnesium greater than that of sulfur?
some elements show irregularities in the general trend because of the following two factors: (1) type of electron to be removed (2)extra stability of exactly half filled and completely filled electronic configuration… so if we write the electronic configuration for both we can see the difference: Mg = 1s2 2s2 2p6 3s2 S = 1s2 2s2 2p6 3s2 3p4 now as magnesium’s 3S orbitals are completely filled so it will resist more to loose an electron so more energy is needed…while in S electron is to get out from 3P which is not completely filled so it is easy to pull an electron…also if one electron is taken out sulphur will atttain a stable half filled 3P orbitals from 3P4 to 3P3 … There are 3 3P orbitals, and each can accommodate two electrons. Electrons, being negatively charged, repel each other. If two electrons move in the same region of space (in this case, in the same 3P orbital), then they will repel each other more strongly than if they move in different regions of space (i.e., in
