Here's why:
* Metals are typically shiny, malleable (can be hammered into shapes), ductile (can be drawn into wires), good conductors of heat and electricity, and tend to lose electrons in chemical reactions.
* Nonmetals are typically dull, brittle, poor conductors of heat and electricity, and tend to gain electrons in chemical reactions.
There are some elements that exhibit properties of both metals and nonmetals, and these are known as metalloids (or semimetals). Examples include silicon, germanium, and arsenic.
