Paramagnetism
Weak attraction into a magnetic field, shown by substances containing one or more unpaired electrons.
Formula / equation
μ = √(n(n+2)) BM
Unit
BM
In depth
Unpaired electron spins act as tiny magnetic dipoles that align with an applied field. The spin-only magnetic moment, measured in Bohr magnetons, gives the number of unpaired electrons directly, making magnetic measurement a standard way to determine the oxidation state and geometry of a transition-metal complex.
Examples in the real world
O₂ is drawn to a magnet because of two unpaired π* electrons; [Fe(H₂O)₆]³⁺ with five unpaired electrons gives μ ≈ 5.92 BM.