Copper, is an element, on the Periodic Table of the Elements. It is number 29, and has the symbol Cu. Pure copper has an reddish-orange color, and it is the one of the metals which are chemically inert enough to exist in nature as a reduced metal (as opposed to Cu compounds in an ore. It can thus be obtained without smelting, the chemical process of extracting a metal from its compounds. Its unusual, attractive appearance and the ability to obtain the metal without smelting led to early human use during the neolithic and paleolithic era from (c. 8000 BC). With the possible exception of gold, it is thought to have been the first metal used. Copper ores can be smelted at temperatures which can be attained with primive techniques. Copper was probably the first metal to be smelted (c. 4500 BC).

During the time of the Romans, it was mined on Cyprus, the original name of the metal, later corrupted to "cuprum", which later became the letter copper as it is today.

Copper has a single 4s electron, which is easily delocalized, making Cu the second most electrically and thermally conductive element (behind Ag). Its 4s electron is not easily removed, unlike the unpaired electron in alkali metals, which means it is not chemically active. It can easily be reduced to the metal.

Pure copper is used for making products such as heatsinks and electrical cables which take advantage of its conductivity. It is also the base metal used in brasses and bronzes. Molten tin/lead alloys will wet copper, which allows parts made of copper (or brass) to be joined electrically or mechanically by the low-temperature process known as soldering. Solder is second in importance only to high-purity silicon in its importance to electronics.