Question

Between cu+,zn2+,fe2+,and fe3+ which has highest magnetic moment

Answer 1

Fe2+ has the highest paramagnetic character followed by Cr3+ and least is for Cu2+.
The paramagnetic character is determined by the number of unpaired electrons in the species and its magnetic moment. More the number of unpaired electrons more is the paramagnetic character. The magnetic moment is given by the formula
μ = n(n+2)−−−−−−−√ where n is the number of unpaired electrons.
Cu2+ has the d orbital electronic configuration, 3d9 and has 1 unpaired electron, μ = 1.73 BM
Fe2+ : 3d6, 4 unpaired electrons, μ = 4.9 BM
Cr3+: 3d3, 3 unpaired electrons, μ = 3.87 BM
Hope it help u