Duduli

Answer:- Those elements in which last electron enters into the d-sublevel of the penultimate main energy level are called  d-block elements.

Answer:- Interstitial compounds are those compounds which are formed when small atoms (like H,B,N & C etc.) are trapped inside the crystal lattices of metals.

Answer:- Because of large number of unpaired electrons in atoms of transition element they have stronger interatomic interaction and hence stronger bonding between atoms resulting in higer enthalpies of atomisation.

Answer:- The elements which have partially filled (1-9) d-orbital in their ground state or in their stable oxidation state are called transition elements.

Answer:- The d-block elements are present in between S-block & p-block so these elements are show both the character of S-block & P-block elements due to this transition behaviour of d-block elements these are called transition elements.