Metals are elements that typically have luster, conduct heat and electricity well, are malleable (can be hammered into thin sheets), ductile (can be drawn into wires), and tend to lose electrons during chemical reactions becoming cations.
Related terms
Alkali Metals: These are very reactive metals found in Group 1 of the periodic table; they readily lose one electron to form +1 cations.
Transition Metals: These are metallic elements found in the middle block of the periodic table; they often have multiple oxidation states due to variable loss of their d-electrons.