Which of the following sets has strongest tendency to form anions? (a) \(\mathrm{V}, \mathrm{Cr}, \mathrm{Mn}\) (b) \(\mathrm{N}, \mathrm{O}, \mathrm{F}\) (c) \(\mathrm{Ga}, \mathrm{In}, \mathrm{Tl}\) (d) \(\mathrm{Na}, \mathrm{Mg}, \mathrm{Al}\)

Electronegativity is a chemical property that describes an atom's ability to attract and hold onto electrons. It is a relative measure that can predict how an atom will interact when it comes into contact with other atoms. Atoms with high electronegativity, such as fluorine, oxygen, and nitrogen, have a stronger pull on electrons.

This property plays a critical role in anion formation because an atom must be able to attract electrons to gain extra ones and become negatively charged. In general, the further to the right and up you go on the periodic table—except for the noble gases—the higher the electronegativity. This trend helps explain why nonmetals, particularly halogens and oxygen-group elements, are more likely to form anions.

Nonmetals are elements primarily found on the right side of the periodic table and are characterized by their lack of metallic properties. They are usually poor conductors of heat and electricity, have higher electronegativities, and are more likely to gain electrons in chemical reactions, leading to anion formation.

Nonmetals differ vastly in their physical properties; some are gases (like nitrogen and oxygen), while others are solids (such as sulfur and phosphorus) at room temperature. When nonmetals react with metals, they tend to gain electrons, due to their high electronegativity, and form anions, which are necessary for the completion of their valence electron shells, leading to a more stable electron configuration.

The periodic table is organized into vertical columns known as 'groups' or 'families' that share similar chemical properties. Nonmetals are located in groups 14-18, with groups 16 (chalcogens) and 17 (halogens) being particularly known for their tendency to form anions.

The atoms in these groups have valence shells that are close to being filled, which means they have a high affinity for electrons. Group 17 elements (halogens) need only one more electron to achieve a full shell, giving them very high electronegativities which account for their profound ability to form anions when reacting with metals or with elements of lower electronegativity.