* Metals: These elements are typically shiny, malleable, ductile, and good conductors of heat and electricity. They tend to lose electrons easily and form positive ions. Examples include iron, gold, copper, and aluminum.
* Nonmetals: These elements are generally dull, brittle, and poor conductors of heat and electricity. They tend to gain electrons easily and form negative ions. Examples include oxygen, chlorine, sulfur, and phosphorus.
There is also a third category called Metalloids (sometimes called semi-metals), which have properties of both metals and nonmetals. These elements are often semiconductors. Examples include silicon, germanium, and arsenic.
