What type of atoms are known to be poor conductors due to having more than 3 electrons in their outer shell?

The correct answer is that atoms with more than three electrons in their outer shell are typically poor conductors, categorizing them as insulators. In atomic structure, elements have electrons organized in shells, with the outermost shell influencing their conductivity.

Atoms that have more than three electrons in their outer shell tend to hold onto these electrons more tightly. This characteristic results in less free movement of electrons, which is essential for conduction of electricity. Insulators, such as nonmetals, are known for having higher electronegativity and a complete or nearly complete outer shell, which inhibits the flow of electric current.

In contrast, metals usually have one to three electrons in their outer shell, allowing for greater electrical conductivity, while semiconductors can conduct electricity but only under certain conditions, and nonmetals often have varied conductive properties. Therefore, insulators are distinctly defined by their outer electron configuration, making them poor conductors.