Question

Discuss the important physico-chemical characteristics of transition elements.

Answer 1

1. They have partly filled (n − 1)d orbitals in atomic or ionic form.
2. Atomic and ionic radii decrease across a series but remain nearly constant between the 2nd and 3rd series due to lanthanoid contraction.
3. High melting and boiling points due to strong metallic bonding with covalent character.
4. Variable oxidation states, commonly +2, arise from loss of ns electrons and involvement of (n − 1)d electrons.
5. Most ions are colored due to d-d electronic transitions.
6. Paramagnetic behavior arises from unpaired d electrons; it varies across the series.
7. The density generally increases across a series due to increased nuclear charge and decreasing atomic volume.
8. Strong metallic and covalent bonding cause hardness.
9. Ionization energies are intermediate, increasing across the series, but not regularly.
10. Complex formation is common owing to partially filled d orbitals.