Why do the transition metals show fairly consistent ionization energies and atomic radii?
Igloo writes To understand whats going on here you need to understand the concept of effective nuclear charge. This is the amount of positive charge (in the nucleus) actually experienced by any particular electron. This will of course depend on the number of protons in the nucleus and on the number of electrons between the nucleus and the electron concerned. The intervening electrons are said to shield the outermost electrons from the attractive force exerted by the nucleus, with the result that these outer electrons do not experience the full nuclear charge. As you go across the d-block elements from scandium to zinc, the elements gain one proton in the nucleus and, of course, one extra electron, but these additional electrons are entering the 3d sub-shell, and they help to shield the outermost 4s electrons (which are the ones first lost from the atom during ionization) from the increased nuclear charge. As a result the effective nuclear charge remains fairly constant across the d-blo
