What is Copper

Copper (pronunciation KOP-er ^[2]), represented by the chemical symbol or formula Cu ^[1], is a soft, malleable and ductile element belonging to the family of transition metals ^{[3, 4, 7]}. Naturally, occurring Cu is a mixture of 2 stable isotopes with mass numbers 63 and 65 ^{[1, 3]}. Besides that, it has 24 synthetic, radioactive isotopes with known half-lives ^[3]. Under normal conditions, it is stable in air, but in red-hot condition, it reacts with oxygen to form its oxide. It also reacts with halogens and acids ^[21].

Where Is It Found

The metal rarely occurs freely in nature. Its principal ores are minerals such as bornite and chalcopyrite. Cu is isolated from these ores by smelting, leaching and electrolysis ^{[1, 3]}.

History

Origin of Its Name: The name is derived from its old English name ‘coper’ that is in turn derived from the Latin words ‘Cyprium aes’ that means a metal from Cyprus ^[1].

Who Discovered Copper: Unknown ^[1].

When Was It Discovered: In prehistoric times ^[1].

How Was It Discovered

Historically, Cu was the first metal to be worked by humans. The discovery that it could be hardened by the addition of tin to form the alloy bronze led to the naming of the Bronze Age when it was used in making coins, cutlery and tools. Copper beads excavated from northern Iraq were found to be more than ten thousand years old ^[1].

Copper Identification
Atomic Number	29 [1]
CAS Number	7440-50-8 [1]
Position in the periodic table	Group	Period	Block
	11 [1]	4 [1]	d [1]

Properties and Characteristics of Copper

General Properties
Atomic mass		63.546  atomic mass units [1]
Atomic weight		63.546 [1]
Mass number		63 [3]
Molar mass/molecular weight		63.546 g/mol [20]
Physical Properties
Color/appearance		Orange-red [3]
Luster		Bright metallic [3]
Melting point/freezing point		1084.62°C, 1984.32°F [1]
Boiling point		2560°C, 4640°F [1]
Density		8.96 g cm-3 [1]
State of matter at room temperature (normal phase)		Solid [1]
Thermal Conductivity		385 W/(m K) [8]
Electrical Conductivity		5.96X107S/m [9]
Specific heat capacity		0.385 J/g oC [10]
Specific gravity		8.89 [11]
Resistivity		1.72X10-8 ohm-m [12]
Hardness (Mohs scale)		3 [13]
Yield strength		40-80 MPa [14]
Tensile strength		200 MPa [14]
Temperature coefficient		+0.393%/oC [15]
Coefficient of linear expansion		17X10-6/oC [16]
Chemical Properties
Oxidation state/Oxidation number		+1, +2, +3, +4 [1]
Flammability		No [17]
Magnetic Properties
Magnetic ordering	Diamagnetic [18]

Atomic Data of Copper (Element 29)

Uses of Copper

1. Commonly used for making coins ^[1].
2. For electrical equipment such as motors and wiring due to its high electrical and thermal conductivity ^[1].
3. For construction purposes (like plumbing and roofing) and industrial machinery (like heat exchangers) ^[1].
4. Copper sulfate finds wide application as an agricultural poison and algaecide in water purification ^[1].
5. Copper compounds, for example, Fehling’s solution, are used in chemical tests that detect sugar ^[1].

Is It Dangerous

Though the element is essential to all plants and animals, excess amounts are toxic. Cooking acidic food in copper utensils can cause poisoning. That is why copper cookware should be lined to prevent the ingestion of dangerous verdigris (compounds formed by copper corrosion). An adult human being needs around 1.2 milligrams of copper daily ^{[1, 3]}. You can prevent copper deficiency by taking foods high in copper such as whole grains, nuts, beans, potatoes, oysters and other shellfish ^[22].

Interesting Facts

• Unlike human beings that use the iron present in blood hemoglobin to transfer oxygen in their bodies, some crustaceans use copper complexes ^[1].
• The surface of copper, when left exposed to air, gradually tarnishes to a dull, brownish color ^[3].

Cost of Copper (Cu Element)

The pure metal is priced at $9.76 for every 100 gram and in bulk, the same quantity is worth $0.66 ^[3].

References
1. http://www.rsc.org/periodic-table/element/29/copper
2. https://education.jlab.org/itselemental/ele029.html
3. https://www.chemicool.com/elements/copper.html
4. https://www.lenntech.com/periodic/elements/cu.htm
5. https://environmentalchemistry.com/yogi/periodic/Cu.html
6. https://www.enotes.com/homework-help/valency-copper-585843
7. http://chemistry-reference.com/q_elements.asp?Symbol=Cu
8. http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/thrcn.html
9. https://www.thoughtco.com/table-of-electrical-resistivity-conductivity-608499
10. http://www.iun.edu/~cpanhd/C101webnotes/matter-and-energy/specificheat.html
11. https://www.engineeringtoolbox.com/specific-gravity-solids-metals-d_293.html
12. https://www.electronics-tutorials.ws/resistor/resistivity.html
13. http://periodictable.com/Properties/A/MohsHardness.v.html
14. https://kupfer.de/kupferwerkstoffe/kupfer/eigenschaften/?lang=en
15. https://www.cirris.com/learning-center/general-testing/special-topics/177-temperature-coefficient-of-copper
16. http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/thexp.html
17. nj.gov
18. https://www.quora.com/Is-copper-magnetic
19. http://periodictable.com/Properties/A/LatticeConstants.html
20. https://www.webqc.org/molecular-weight-of-Cu.html
21. https://www.webelements.com/copper/chemistry.html
22. https://medlineplus.gov/ency/article/002419.htm