Why do Mn and Tc have lower Melting points than expected even when they have extra stability due to have filled subshells?
Answers
Answer:
Well, It is a very common question in the minds of all good chemistry students. Firstly it should be understood that this is an anomaly. And anomalies in chemistry are reasoned by other factors. It can be understood by.
1)Melting point depends on extent metallic bonding, and the idea about metallic bonding can be understood by the enthalpy of atomization values. If u look at values, Mn has lower value among other elements of the period.
2)The other reason is very obvious, the half-filled d orbital electrons are very tightly bound to the nucleus. Thus these 5 d electrons are very less delocalised and can not help in effective metallic bonding. Therefore, Mn has less melting point in spite of having 5 unpaired d electrons.
Explanation: