Why are the d-block elements paramagnetic

1 answer

The d-block elements, also known as transition metals, can be paramagnetic due to the presence of unpaired electrons in their d orbitals. Let's break this down:

  1. Electron Configuration: Transition metals have partially filled d orbitals in their electron configurations. The typical general configuration is \( (n-1)d^{1-10} ns^{0-2} \).

  2. Unpaired Electrons: Paramagnetism arises from the presence of unpaired electrons. According to Hund's rule, electrons will occupy degenerate orbitals singly before pairing up. If there are unpaired electrons in the d orbitals, the element will exhibit paramagnetism.

  3. Magnetic Behavior: In general, a substance is considered paramagnetic if it contains unpaired electrons that align with an external magnetic field, leading to a weak attraction to the field. The more unpaired electrons present, the stronger the paramagnetic effect.

  4. Examples:

    • Iron (Fe) has the electron configuration [Ar] 4s² 3d⁶, which has four unpaired electrons in the d orbital, making it strongly paramagnetic.
    • Copper (Cu) has the configuration [Ar] 4s² 3d¹⁰, which is not paramagnetic because all electrons are paired.

In conclusion, d-block elements are paramagnetic due to the presence of unpaired electrons in their d orbitals. The extent of their paramagnetism depends on the specific electron configuration and the number of unpaired electrons.