Question

Account for the paramagnetic character of transition metal compounds.

Answer 1

The paramagnetic character of transition metal compounds arises due to the presence of unpaired electrons in their d-orbitals. Paramagnetism refers to the property of a substance being attracted by an external magnetic field, and this attraction is caused by magnetic moments associated with unpaired electrons.

The degree of paramagnetism depends on the number of unpaired electrons in the transition metal ion. The more unpaired electrons there are, the stronger the paramagnetic behaviour. For example, Mn²⁺ (3d⁵) has five unpaired electrons and is strongly paramagnetic, while Cu²⁺ (3d⁹) has only one unpaired electron and shows weak paramagnetism. This behaviour is common across the transition elements because their d-orbitals are progressively filled across the period, leading to variations in the number of unpaired electrons and hence, the paramagnetic character.