metals and nonmetals

Metals are elements that are generally shiny, malleable, ductile, and good conductors of heat and electricity.

Nonmetals are elements that are generally dull, brittle, and poor conductors of heat and electricity.

Iron (Fe), Copper (Cu), and Aluminum (Al).

Oxygen (O), Carbon (C), and Sulfur (S).

Metals are good conductors of electricity due to their free-moving electrons.

Nonmetals are poor conductors of electricity and heat, making them good insulators.

Malleability

Ductility

Metallic bonds, where electrons are delocalized in a "sea of electrons."

Most metals are solid, while nonmetals can be solid, liquid, or gas at room temperature.