Answer: Option (B) is the correct answer.
Explanation:
Metallic bond is defined as the bonds formed by positively charged atoms due to sharing of delocalised electrons among the lattice of cations.
Formation of metallic bonds depend on two factors which are number of valence electrons released in metallic bonding and the number of protons present within the nucleus of an atom.
So, more is the number of valence electrons more they will be able to pull the protons of the cation as opposite charges attract each other. Hence, stronger will be the metallic bond.
Magnesium has 2 valence electrons and acquires a +2 charge only. And, iron can have either +2 or +3 charge. Whereas magnesium have just 12 protons and iron have 26 protons.
Therefore, iron will be able to form strongest metallic bond due to more valence electrons and more number of protons.
