metal
Metals generally include materials that are hard, glossy, and have high thermal and electrical conductivity. In chemistry it is used to refer to transition metals and post-transition metals, but occasionally they include metalloids in the definition of metals. Generally, it is solid at room temperature. It has a unique luster and is a conductor that transmits heat and electricity well. It has ductility and electrical conductivity. About three-quarters of the 118 elements located on the periodic table correspond to the definition of a common metal. Iron, copper, aluminum, gold, tin, and uranium are commonly found in nature. Usually metal elements lose electrons and tend to become positive ions, while non-metals are easy to obtain electrons. In astronomy, elements that are heavier than hydrogen and helium are called metals.