Answer:
C. ns² np^5
Explanation:
An electron gets more electro-negative as it increases in number of electrons until it shell gets filled up. At the point when its shell is filled up, the electron becomes neutral; i.e. not positive and not negative.
Only ns² np^5 satisfies this condition; reason being that it has higher electrons
Be(g) + e + 241 kJ ==> Be^-(g) EA = +231 kJ/mol. (endothermic)
Considering the example above
Also, electron affinity is referred to as the amount of energy absorbed when there's an additional electron to an isolated gaseous atom which forms an ion with a 1- charge by assigning a positive value when energy is absorbed and a negative value when energy is released