In condensed matter physics, the Slater–Pauling rule states that adding an element to a metal alloy will reduce the alloy's saturation magnetization by an amount proportional to the number of valence electrons outside of the added element's d shell.
[1] Conversely, elements with a partially filled d shell will increase the magnetic moment by an amount proportional to number of missing electrons.
Investigated by the physicists John C. Slater[2] and Linus Pauling[3] in the 1930s, the rule is a useful approximation for the magnetic properties of many transition metals.
The use of the rule depends on carefully defining what it means for an electron to lie outside of the d shell.
Ordered in terms of energy, the electron configuration of Zinc is [Ar] 3d10 4s2.