Question

Which ion, Co²⁺ or Zn²⁺, is attracted to a magnetic field? Give reasons.

(Atomic Number of Co = 27 and Zn = 30)

Answer 1

Co²⁺ is the ion attracted to a magnetic field. Because attraction to a magnetic field (paramagnetism) requires one or more unpaired electrons, repulsion (diamagnetism) occurs when all electrons are paired. Co²⁺ (Z = 27) has configuration [Ar] 3d⁷ and therefore has three unpaired d‑electrons (paramagnetic). Zn²⁺ (Z = 30) has a configuration [Ar] 3d¹⁰ with all d electrons paired (diamagnetic).