question_answer 22)

  What are interstitial compounds? Why are such compounds well known for transition metals?

Answer:

In the crystal lattice, transition elements have the interstitial vacant spaces into which small sized non-metal atom (H, C, N, B) can fit, resulting in the formation of interstitial compounds e.g., cast iron (Fe + C) and steel. These have the chemical properties similar to that of the parent transition metal but different physical properties such as the hardness, electrical conductivity.