As elements gain more electrons in their outer shells, their electrical conductivity generally decreases. Which of the following explains this phenomenon? A. Atoms with more electrons in each shell are more stable and are less likely to release electrons. B. An atom with more mass exerts a larger attractive force on free electrons. C. As the number of electrons increases in an atom, its net charge is more negative, becoming more repulsive to negative charges. D. As the number of electrons grow in an element, there is less room for free electrons to move and conduct electricity.

As elements gain more electrons in their outer shells, their electrical conductivity generally decreases. Which of the following explains this phenomenon? A. Atoms with more electrons in each shell are more stable and are less likely to release electrons. B. An atom with more mass exerts a larger attractive force on free electrons. C. As the number of electrons increases in an atom, its net charge is more negative, becoming more repulsive to negative charges. D. As the number of electrons grow in an element, there is less room for free electrons to move and conduct electricity.