Copper: Facts about the reddish metal that has been used by humans for 8,000 years

The first metal to be manipulated by humans was copper.

The oldest metal object in the Middle East is copper, and the U.S. penny was made of pure copper.

According to the U.S. Geological Survey, copper is the third-most-consumed industrial metal in the world. Most of the copper goes to make electrical wires, telecommunication cables and electronics.

copper is the only metal on the periodic table that is not silver or gray.

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Chemical description of copper

• Atomic number (number of protons in the nucleus): 29
• Atomic symbol (on the periodic table of elements): Cu
• Atomic weight (average mass of the atom): 63.55
• Density: 8.92 grams per cubic centimeter
• Phase at room temperature: solid
• Melting point: 1,984.32 degrees Fahrenheit (1,084.62 degrees Celsius)
• Boiling point: 5,301 F (2,927 C)
• Number of isotopes (atoms of the same element with a different number of neutrons): 35; 2 stable
• Most common isotopes: Cu-63 (69.15% natural abundance) and Cu-65 (30.85% natural abundance)

The history of copper

Most copper occurs in ores and must be smelted before it can be used. According to the chemistry database site, natural chemical reactions can sometimes release native copper.

Humans have been making things from copper for at least 8,000 years and figured out how to smelt it. The Bronze Age was a period from 3300 to 1200 B.C. and was marked by the use of bronze tools and weapons.

There are copper artifacts in the historical record. The awl was buried with a woman in an ancient village in Israel. The oldest metal object in the Middle East is the awl. The Caucasus region is located in the mountainous region covering southeastern Russia, Armenia, Azerbaijan, and Georgia, and it is believed to be where the copper came from. People used copper to make jewelry in ancient Egypt. Huge copper mines from the 10th century B.C. were found in Israel. Around 7,000 years ago, humans unleashed the first pollutant on the environment.

According to the US Geological Survey, about two-thirds of the copper on Earth is found in volcanic rocks. The metal conducts heat and electricity well, which is one of the reasons why copper is used in electronics and wiring.

When copper is exposed to water and air, it loses electrons and turns green. The Statue of Liberty is green because of the oxidation reaction. Lady Liberty is covered with a weathered layer of copper oxide that is only 0.05) inches thick. 34 years after the statue was dedicated, the change from copper-colored to green was complete, according to the New York Historical Society.

Fast facts about copper

There are some interesting facts about copper.

•  According to Peter van der Krogt, a Dutch historian, the word "copper" has several roots, many of which come from the Latin word cuprum that was derived from the phrase Cyprium aes, which means "a metal from Cyprus," as much of the copper used at the time was mined in Cyprus.
• If all of the copper wiring in an average car were laid out, it would stretch 0.9 miles (1.5 km), according to the USGS.
• The electrical conductance (how readily a current can flow through the metal) of copper is second only to that of silver, according to the Jefferson Laboratory.
• Pennies were made of pure copper only from 1783 to 1837. From 1837 — 1857 pennies were made of bronze (95% copper, with the remaining 5% made up of tin and zinc). In 1857, the amount of copper in pennies dropped to 88% (the remaining 12% was nickel). In 1864, the recipe reverted to its previous recipe. In 1962, a penny's content changed to 95% copper and 5% zinc. From 1982 through today, pennies are 97.5% zinc and 2.5% copper.
• People need copper in their diets. The metal is an essential trace mineral that's crucial for forming red blood cells, according to the U.S. National Library of Medicine. Fortunately, copper can be found in a variety of foods, including grains, beans, potatoes and leafy greens.
• Too much copper, however, is a bad thing. Ingesting high levels of the metal can cause abdominal pain, vomiting and jaundice (a yellowish tinge to the skin and white of the eyes that may indicate the liver is not functioning correctly) in the short term. Long-term exposure may lead to symptoms such as anemia, convulsions and diarrhea that is often bloody and may be blue.
• Occasionally, increased levels of copper are found in the water supply due to old copper pipes. For example, in August 2018, the public school system in Detroit turned off all drinking water in public schools as a precaution due to high levels of copper and iron found in the water, according to the Seattle Times.
• Copper has anti-microbial properties and kills bacteria, viruses and yeasts on contact, according to a 2011 paper in the journal Applied and Environmental Microbiology. As a result, copper can even be woven into fabrics to make anti-microbial garments, like socks that fight foot fungus.
• Copper is also included in certain types of intrauterine devices (IUDs) used for birth control, according to the Mayo Clinic. The copper wiring creates an inflammatory reaction that is toxic to both sperm and eggs, in order to prevent pregnancy. There is, with any medical procedure, a risk of side effects. (Copper toxicity doesn't appear to be one, according to a 2017 article published in Medical Science Monitor).

Current research

The anti-microbial properties of copper have made it a popular metal in the medical field. Hospitals have been experimenting with covering frequently touched surfaces, such as bed rails and call buttons, with copper or copper alloys in an attempt to slow the spread of hospital-acquired infections. A professor of infectious diseases and a hospital epidemiologist at the Medical University of South Carolina said copper kills microbes by interfering with the electrical charge of the organisms.

A team of researchers led by Salgado tested the surfaces in intensive-care units in three hospitals, comparing rooms modified with copper to rooms not modified with copper. In the traditional hospital rooms without copper surfaces, 12.3% of patients developed antibiotic-resistant infections such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Only 7.1% of patients contracted one of these potentially devastating infections in the copper-modified rooms.

We know that if you put copper in a patient's room, it will decrease the amount of bugs in the room. Our study was the first to show that there could be a benefit.

The researchers didn't change anything about the conditions in the intensive care unit, doctors and nurses washed their hands, and cleaning went on as usual. The researchers published their findings in the journal. The researchers found that there were fewer germs on stethoscopes that were coated with copper. The stethoscopes were completely free ofbacteria. In areas where patients are more mobile than in the intensive care unit, research is continuing to test the idea of copper plating. There needs to be a cost-benefit analysis weighing the expense of copper installation against the savings gained by preventing costly infections.

Dressing wounds in copper-rich bandages can reduce the risk of an abdominal infections by 80% compared to traditional dressings. The results were published in a journal.

Researchers are trying to integrate copper into more cutting-edge devices because of its abundance and low price.

According to a professor of chemical engineering at a university in Australia, copper can be used to make electronics. Cheng and his colleagues have used copper nanowires to create anaerogel monolith that is light and strong enough to stand on its own, similar to a dry kitchen sponge. In the past, these monoliths have been made from gold or silver, but copper is a more economical option.

The researchers created aerogel monoliths that could turn into sliceable, shapeable rubber by mixing copper and alcohol. The researchers reported their findings in the journal. Cheng told Live Science that the ultimate result could be a soft-bodied robot or a medical sensor that melds perfectly to curved skin. He and his team are working to create blood pressure and body temperature sensors out of copper aerogel monoliths, another way copper could help monitor human health.

Physicists have been using copper. A chunk of copper became the world's lowest temperature in an experiment in which researchers chilled it to six thousandths of a degree above absolute zero. This is the closest substance of this mass and volume has ever been.

The Italian National Institute for Nuclear Physics put the weight in. A cryostat is a container that is specially designed to keep items extremely cold. This is the first cryostat that can keep substances so close to absolute zero. The experiment was part of a research project to understand why there is so much more matter than antimatter in the universe.

Agricultural scientists are interested in copper. Researchers at Cornell University are studying the effects of copper deficiency on wheat. Wheat is one of the most important food items in the world, and copper deficiency can lead to a lower crop yield and lower crop fertility.

Plants absorb and process copper. The Department of Agriculture says that they have found two wheat proteins that are vital to the delivery of copper to the wheat's reproductive organs.

Crop yields increase by as much as seven times when copper is enriched in the soil and then absorbed by wheat, according to early tests. The knowledge of copper and other minerals is beneficial for the health and fertility of crops, but how and why is not well understood. The knowledge of why copper is beneficial and how it functions within a plant can be used on crops such as rice, barley and oats, and can be introduced to soil that was once unsuitable for farming.

The article was updated on March 9, 2022, by a Live Science contributor. Rachel Ross is a contributor to Live Science.

Further reading

• The American Cancer Society examines the research about copper and claims that it may have a role in preventing or treating cancer.
• The Environmental Protection Agency provides information about exposure to high levels of copper and the effects of copper corrosion in household pipes.
• The Thomas Jefferson National Accelerator facility (Jefferson Lab) explores the history and uses of copper.

Bibliography

The Royal Society of Chemistry has copper information. March 9, 2022.

There are health benefits and risks of copper. October.

The National Library of Medicine has copper. March 9, 2022.