If an atom has an electron configuration of 2.8.2, what will it be most likely to bond with?

A. One fluorine atom
B. One arsenic atom
C. None of these
D. Two chlorine atoms

B. Two chlorine atoms

Explanation:

This electronic configuration shows that the given atom is magnesium.

Electronic configuration of magnesium:

Mg¹² = 1s² 2s² 2p⁶ 3s²

There are two valance electrons of magnesium that's why it would react with two atoms of chlorine. Chlorine is present in seventeen group. It has seven valance electrons. It required just one electron to get complete octet. While magnesium needed to lose two electrons to get complete octet. That's why two chlorine atoms bonded with one magnesium atom. Thus both would get complete octet.

Mg + Cl₂  →   MgCl₂

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.