Hello Riya,

Transition elements exhibit higher enthalpies of atomisation due to the following reasons:

1. Strong Metallic Bonding:

   • Transition metals have more unpaired d-electrons, leading to stronger interatomic interactions.
     
     
   • This results in a higher amount of energy required to break the metallic bonds.
     
     

2. Partially Filled d-Orbitals: The (n-1)d and ns electrons participate in bonding, increasing metallic bond strength.
   
   

3. High Number of Unpaired Electrons: Elements in the middle of the series (like Fe, Co, Ni) have maximum unpaired d-electrons, leading to strong bonding and higher enthalpy of atomisation.

Thus, transition metals need more energy to separate atoms, leading to high enthalpies of atomisation compared to s- and p-block elements.

I hope this answer helps you. If you have more queries then feel free to share your questions with us we will be happy to assist you.

Thank you and wishing you all the best for your bright future.