Explain the key physical differences between metals and non-metals, providing at least three distinct properties for each.

Metals are generally lustrous, malleable, ductile, good conductors of heat and electricity, and solid at room temperature (except mercury). Non-metals are typically dull, brittle, non-ductile, poor conductors of heat and electricity (except graphite), and can exist as solids, liquids, or gases at room temperature.