Which group of elements is characterized by being poor conductors and tends to gain electrons during reactions?

The group of elements characterized by being poor conductors of electricity and heat, as well as their tendency to gain electrons during chemical reactions, is nonmetals. Nonmetals typically have high electronegativities, meaning they are more likely to attract electrons rather than lose them. This reactivity aligns with their tendency to form negative ions or anions through the process of gaining electrons.

Nonmetals encompass various elements, including gases like oxygen and nitrogen, as well as solids like carbon and sulfur. These elements usually do not exhibit the metallic luster and conductivity that are characteristic of metals. Instead, they often exist in various states at room temperature, contributing to their classification as poor conductors.

The other categories—such as metals, which generally conduct electricity well and tend to lose electrons; metalloids, which share properties of both metals and nonmetals; and transition metals, known for their ability to form various oxidation states—do not fit this description of gaining electrons and being poor conductors as accurately as nonmetals do.