18. Which one of the following has a maximum tendency to form M3 ion ? A.N B.Bi C.P D.As
Answer: Option A Solution: The general electronic configuration of group 15 elements (N, P, As, Sb and Bi) is ns2np3. Since Nitrogen has smallest size and greatest electronegativity in the family, it may gain three electrons and attain noble gas configuration, forming nitride N3- ions. The other members show little tendency to form tri-negative M3- ions. Their electronegativity is so low that they would generally form covalent compounds even with highly electropositive elements.
