MARCH 2024 — Chemistry STD 12 Science — Question

→ "Transition metals are large in size and contain lots of interstitial sites. Transition elements can trap atoms of other elements (that have small atomic size), such as H, C, N, in the interstitial sites of their crystal lattices. The resulting compounds are called interstitial compounds."
→ They are usually non stoichiometric and are neither typically ionic nor covalent,
→ For example, TiC, Mn₄N, Fe₃H, VH_0.56 and TiH_1.7. etc.
→ These compounds are referred to as interstitial compounds.
→ The principal physical and chemical characteristics of these compounds are as follows:
→They have high melting points, higher than those of pure metals.
→They are very hard, some borides approach diamond in hardness.
→They retain metallic conductivity.
→They are chemically inert.