Copper
Copper, which has a red-orange metallic color, is represented by the symbol Cu. Copper has an atomic number of 29 and an atomic mass of 63.546, giving it 29 protons, 29 electrons, and 35 neutrons. Copper is an unusual element because the electrons in its 3d orbital pair up with the electrons in its 4d orbital instead of leaving the 4d orbital full, this is so the Cu atom can remain more stable. Thus, its electron configuration is 1s22s22p63s23p64s13d10. It has a melting point of 1357.75K, a boiling point of 2840K, and its freezing point is the same as its melting point, 1357.75K. Copper has two naturally occurring isotopes: copper-63 which has 34 neutrons and an abundance of 69.09%; and copper-65, which has 36 neutrons and an abundance of 30.91% (Barbalace).
Copper is believed to have been discovered around 9000 B.C. in the areas surrounding Jordan, Israel, and Egypt. Copper is useful in many areas because it is ductile, malleable, and conducts heat and electricity well. It was used by the ancient Egyptians as tubing and is still found today in working condition because of copper’s non-corrosive qualities (Stanczak). Copper, when placed in damp places, protects itself from damage by coating itself with patina, a green film-like substance (“Copper”). It is used today in electrical wiring, plumbing pipes, cooking ware, and with its alloys bronze and brass. It was also used widely in coins of monetary value and copper sulphate is used to purify water and as a toxin by farmers. The phrases “coppers” and “cops” resulted from the copper buttons worn by police officers. In the sun copper is found in 10 parts per billion by atoms, 31,000 parts per billion by atoms in meteorites, 0.29 parts per billion by atoms in ocean water, 0.09 parts per billion by atoms in rivers, and 99 parts per billion by atoms in humans (Winter).