Question

Explain the following: Many of the transition elements are known to form interstitial compounds.

Answer 1

The compounds formed when small atoms of H, C or N get trapped inside the crystal lattice of metals are known as interstitial compounds.

A number of interstitial compounds are formed by the transition metals. Transition metals react with elements such as hydrogen, carbon, nitrogen, boron etc. to form interstitial compounds.The chemical properties of the parent transition metals are not altered during the formation of interstitial compounds. However, there are various changes in the physical properties such as density, rigidity, hardness, malleability, ductility, electrical conductivity etc. Steel and cast iron are the interstitial compounds of iron which are formed with carbon. In the formation of these compounds, the malleability and ductility of iron is lost to a great extent, but the tenacity of the metal increases.

 Transition metals are d block metals they have large surface area compared to other metals or elements
Due to which small elements get trapped between them forming an interstitial compound .

Answer 2

Answer: In crystal lattice, transition elements have interstitial vacant space into which small sized non metal atoms such as H, B , C and N are trapped

•This is because of unpaired electrons in d-orbital

•These compounds are non stoichiometric, neither typically ionic nor covalent. Eg: TiC, MH etc

Hope it helps.