y do some elements like Be, N and P have electron affinity zero?

Question

i need proper reasons n some websites on this also.

Answer 1

Uhh.. actually, Be and Group II elements have a positive electron affinity, due to a filled s orbital electron shell. Same with Group 12 (starting with Zn). N and P are also positive, because even partially filled orbitals provide some stability.

The only elements that have an electron affinity close to zero are the noble gases (since they have fully filled orbital shells and already fulfill the octet rule for themselves) and the alkali metals (since they have an extra electron, it's much more energetically favorable to donate it than take an extra one)

Answer 2

the clarification Be, Mg have very low electron affinity is via the coolest digital state they're in (finished S orbital). N and P are electronically good via fact all 3 p orbitals are 0.5 occupied, that's a fairly good state (orbitals are equivalent one to a minimum of one yet another)