What is Copper: Definition and 509 Discussions

Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.
Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals). This led to very early human use in several regions, from c. 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, c. 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create bronze, c. 3500 BC.In the Roman era, copper was mined principally on Cyprus, the origin of the name of the metal, from aes сyprium (metal of Cyprus), later corrupted to сuprum (Latin). Coper (Old English) and copper were derived from this, the later spelling first used around 1530.Commonly encountered compounds are copper(II) salts, which often impart blue or green colors to such minerals as azurite, malachite, and turquoise, and have been used widely and historically as pigments.
Copper used in buildings, usually for roofing, oxidizes to form a green verdigris (or patina). Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents, fungicides, and wood preservatives.
Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the iron-complexed hemoglobin in fish and other vertebrates. In humans, copper is found mainly in the liver, muscle, and bone. The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight.

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  1. J

    Growler make your own

    I see different growlers and the one that seems the best uses 28 gauge copper wire X 2800 turns hooked to 120 volts AC does this sound right? I think this can be figured out using ohms law to so the windings do not get hot when AC is applied.
  2. A

    I Getting a reduced voltage from a fixed secondary voltage of a transformer

    1) I have a "choke" with many copper windings on a soft iron core. I connect it to the 12V secondary of a mains transformer. I measure the voltage of the choke with a multimeter. What is the value and why? 2) I want to light up a 6V filament lamp. My supply is a 12V from a step down...
  3. A

    Temp change of copper wire w.r.t. time for a constant applied voltage

    Q=m.c.DeltaT, is one approach which could possibly give the relation between Power vs Time. Is it correct ?
  4. kikarone

    Help please with SI-ATRP (polymerization) of polyacrylamide

    Can CuCl and Me6TREN form radicals? Reaction is at room temp and in water (not buffered)
  5. Wo Wala Moiz

    B Can we use a permanent magnet and a copper rod to create an electret?

    Electrons have a magnetic dipole moment. If a permanent magnet was held against one end of a copper rod, the delocalised electrons close to the magnet would be attracted and concentrate around the magnetic pole. This should result in the creation of a weak electret because of the uneven...
  6. A

    Electrolysis: Dark blue oxide from steel?

    Hi there, I have been trying to make iron oxide through electrolysis, I am using salt water as the electrolyte and an old alloyed steel (I am assuming iron and carbon) square pipe as the anode and a Rebar cathode. Unfortunately the beaker gets filled with this dark bluey color and when...
  7. BriggsMason

    Is there an acid that could dissolve Aluminium & leave Copper alone?

    [Mentor Note: Two thread starts merged into one] I need to remove the Aluminium heat fins from a CPU heat extange lined around some copper water heat pipes. I could use a saw, cnc or grinder to remove them, but it seems that this way could be cleaner, and less probable to ruin the heat pipes...
  8. C

    Calculating Copper Wire Gauge for Resistance Thermometer Bridge Circuit

    a. The resistance thermometer bridge circuit shown in FIGURE 1 has a designed maximum temperature of 200°C, ignoring the effects of connecting wire resistance. If the connecting loop is 250 m determine the smallest gauge (swg) of copper wire which must be used if the indicated maximum...
  9. D

    B Voltage gradient distortion in Copper when part is over a magnet

    I am working with HS students on measuring Current Gradients in Copper for their science project " Current Gradients in the human body during surgical cauterization". Next year I was thing of putting a thin sheet of Copper over strong magnets and using the Voltage gradient to draw the Current...
  10. Astronuc

    Recovery/development of low grade copper ore

    (Bloomberg) -- The warnings keep getting louder: the world is hurtling toward a desperate shortage of copper. Humans are more dependent than ever on a metal we’ve used for 10,000 years; new deposits are drying up, and the type of breakthrough technologies that transformed other commodities have...
  11. M

    Copper Losses in an Electric Generator

    When I use Ohm's law and other related equations to calculate the heating losses in a generator I get the power output of the generator. I assume I'm using the equations wrong, and I was hoping that someone could help set me strait. I think what I would like to know is what determines the...
  12. C

    I Is there traction force between moving electrons & copper wire?

    Common sense: walking on road, there is traction between shoes & earth. I'm wondering: same thing for electric current's electrons & copper wire?
  13. V

    B Generator stator: Copper wire or copper sheets?

    Inside a electric generator. To produce the most electricity catching the greatest number of electrons. Instead of spinning a magnet in front of a copper loop or spinning a copper loop between 2 magnet poles my thinking is flat copper sheets would have more surface area on a single magnetic...
  14. BenDover

    What Occurs When Copper is Completely Deposited in Copper Sulfate Electrolysis?

    What happens at the point all the copper moves out of solution and onto electrode during electrolysis of copper sulfate? Responding with anything other than an answer with an explanation is not wanted. Just an fyi, i learn by people showing me the answer and explaining why they think the...
  15. O

    I Magnet falling though copper pipe

    I do not fully understand why a falling neodymium magnet is decelerated in a vertical copper pipe. It is usually explained by Lenz's law, two induced currents generate an upward force that counteracts the force of gravity. (link) However, I assume this upward force has to be generated by the...
  16. V

    Swinging a hanging copper ring with a bar magnet

    I thought of few scenarios and they ended up as follows: The ring must have an induced current. Due to the symmetry of the ring, if one part of the ring feels a force, the part of the ring radially opposite this part will feel a force opposite in direction, since the current will be opposite in...
  17. M

    Can Na2PdCl4 be used as a substitute for PdCl2 in electroless copper plating?

    These videos show an electroless Cu deposition process onto a printed circuit board. I don't care about actually making a PCB, so the other steps such as PCB drilling, photolithography and electroplating thicker Cu aren't relevant. I'm only interested in the steps of electroless Cu...
  18. E

    Resistance Differences: Nichrome vs. Copper Wire

    i don't understand the answer: Nichrome has a higher resistance than copper wire. There is a greater potential difference across the nichrome than the copper wire. From ,the resistance of nichrome is low enough such that there is significant power output. ^ i feel like the bold parts contradict...
  19. amizy9990

    A copper wire contains 3.0 *10 ^ 22 number of charges on 1 meter wire

    A copper wire contains 3.0 *10 ^ 22 number of charges on 1 meter wire. What speed do the electrons move when there is 2 A current in the wire. t=q/t=3,20*10^3 C/ 2.0 A = 1,5*10^22 s v= 1m/1,5*10^3s= 6,6*10^-4 m/s
  20. J

    Electrical AC Brush Motor: 12 Slots, 24 Copper Bars, 48 Ends

    I have an AC brush motor it has 12 slots where copper wires go and 24 copper bars, if you take 12 wires and go in a slot and come out at different slot and as you go around you filled all the slots now you have 24 ends 2 wires out of each slot which you connect to the 24 copper bars. Heres the...
  21. E

    Linear expansion of steel versus copper with increasing temperature

    Here I'm going to show all that I've understood - 1. 2. 3. What I've attempted - L = Lo (1+ α * ẟT) ẟT = 150°C - 15°C = 135°C (Steel) L = ẟL (1 + 11 * 10^-6 * 135) (Copper) L = ẟL (1 + 17 * 10^-6 * 135) This doesn't get me anywhere, obviously. Am I supposed to understand from the...
  22. Steven Bolgiano

    Does Copper Conduct Heat Better than cPVC?

    Hi Folks, I'm 70, so I often confuse myself! Ha ! My question is: Do materials both absorb and release heat equally? So when I evaluate different materials for thermo efficiency, does a copper pipe's surface absorb solar heat at the same rate it gives off heat? My question is specific to a...
  23. shk

    Force extension graph for copper wire

    I have attached the homework with some of the solution. I have ciuple of questions about it. For part b, what else I can say? I think the copper wite is ductile . Elastic and plastic behaviour have already been mentioned. I need to add another word to describe it. Can say it's hard ? Or...
  24. J

    Removing green copper oxides with Electrolysis, chemicals, etc.

    I soaked the following school medallion in water with salt for 20 plus years in the attic and at that time I didn't know copper could corrode and make green oxides. I also didn't think about it much and just forgot about it. I brought it down just today. I read just a while ago that hot...
  25. willDavidson

    PCB design: multiple layers vs heavier copper

    I am designing a board which will have relatively high current. The options are to use heavier copper (4 oz), use two layers (2 oz), or 4 layers (1 oz). Are there any benefits to using one configuration over the others?
  26. Jehannum

    Differentiate between iron and copper sulphide

    I have a quantity of black, lustrous powder taken from inside a gas pipe. I want to know whether it's from copper pipe or from steel pipe. Is there a very simple test I can do? I'm not a chemist and have no specialist equipment.
  27. B

    Why isn't copper used for surfaces in hospitals?

    If copper kills corona how come we've not spend money on putting it in hospital's etc ? How effective is it would silver be more effective?Our a combination of the both copper disc and a silver disc ?
  28. Astronuc

    Disinfecting effect of copper on SARS-CoV-2 and other viruses

    https://www.smithsonianmag.com/science-nature/copper-virus-kill-180974655/ https://www.nih.gov/news-events/news-releases/new-coronavirus-stable-hours-surfaces The effect of copper seems to be independently verified. One should continue to use hand sanitizer and wear a protective face...
  29. rayjbryant

    Calculating the terminal velocity of a magnet falling through a copper coil

    The magnet being used % magnet dimensions [m] d = .0127; r = .00238; %mass of magnet [kg] m_w = .0017; % other constants u_0 = 1.26E-6; % permeability of free space constant T m/A g = 9.81; % gravitational constant in/s^2 %coil properties [22 gauge wire] [m] a = .00635; %radius w =...
  30. J

    Exploring Anodic & Cathodic Tafel Curves: Uneven Electrodeposition?

    The shapes of the anodic and cathodic Tafel curves are different. What does it mean? Does it mean that the electrodeposition of the copper onto a surface of an electrode is uneven? If yes, I am also thinking that this has something to do with the macrothrowing power? Since it was done in an...
  31. J

    Electrical RF conductivity of copper oxide

    In my search, I have been looking for any data that might explain the RF resistance from 3 to 30 MHz range of the two basic types of copper oxides that form on the outside of bare copper wire. I believe these oxides become semiconductors and have large range of impedances. Due to the nature...
  32. kendreaditya

    Time to Equilibrate 0C Copper & 75C Water

    I have a copper cylinder that is at 0C, how much time will be needed for it to equilibrate with 10kg of water at 75C? Copper cylinder: Mass: 105.7 g Specific heat: 0.385 J/gC Initial Temp: 0C Final Temp: 75C ish SA: 25 cm^2 Water: Mass: 10000g Specific heat: 4.184 J/gC Initial Temp: 75C...
  33. hnnhcmmngs

    Calculating Collision Frequency of Electrons in Copper Cube

    Homework Statement: Verify the claim of Section 7.2 that the electrons of a metal collide with the surface at a rate of about 10^30 per second per square centimeter. Do this by estimating the collision frequency of electrons in a 1.00-cm cube of copper metal with one face of the cube surface...
  34. Majorana

    Insulated copper wire turned into gray powder

    Summary: Insulated copper wires (not plated) inexplicably turned into gray powder. Wires are intact between affected spots. This is a piece of common red/black loudspeaker cable, with PVC insulation, pulled from service after about 18 months from installation. It was used to feed a small...
  35. ValeForce46

    Water inside a pot of copper (Thermodynamics problem)

    I tried to write down the equation of heat exchanged: ##Q_{Cu}=m_{cu}*c_{cu}*(T_f-T_0)## for the pot and ##T_f## is my unknown. ##Q_{H2O}=m_{H2O}*c_{H2O}*(T_e-T_{H2O})## where ##T_e=100 °C## is the temperature of vaporization of the water. But ##Q_{H2O}## is not all the exchanged heat by the...
  36. A

    Determining Resistance of a Copper Wire Without Knowing Its Resistivity

    What i did is: ##R=\rho\frac{l}{\Sigma}=\rho\frac{l}{d_2^2\pi-d_1^2\pi}## The problem is that I don't have ##\rho##. Is there a way to find ##R## without knowing it? Many thanks.
  37. S

    Plumbing Soldering brass fittings to copper

    When soldering a brass fitting (e.g. https://www.pexuniverse.com/1-pex-x-3-4-pex-brass-pex-copper-fitting-adapter-lead-free-brass ) to copper (e.g. a 3/4 inch copper coupling) I think there is a danger that copper gets hot enough to melt the solder, but the brass fitting (being more massive)...
  38. A

    Electroplating of platinum/palladium etc on copper, brass question

    I am not sure where to put this but anyways, maybe someone here has had the experience and can tell me more about what important things would be necessary to do this. I am looking forward to making some electrical contacts that will have to survive a mercury environment in a sealed inert...
  39. S

    Find the speed of a copper loop falling in a magnetic field

    Hi all, so I had this problem and on the exam and I got a solution but I had an mass-term in there which wasn't given. I used Farraday's Law of Induction to get the Voltage induced. Then I used ##rho* \frac{A}{4a} ## for the resistance and divided the Voltage by that to get the current. I then...
  40. S

    I Is a Copper Conductor Directional?

    Hi, A question has arisen an a hifi forum (sorry) that cables can be directional. I dispute this, as the proposed mechanism is diodes in the crystal structure etc. or the drawing process to crate the strands. Assume that it is 99.9% pure copper (CW004A (was C101)) and forms part of a cable with...
  41. S

    Force on a copper loop entering into a magnetic Field B with speed v

    Hi, second problem in one evening, I'm sorry! But I'm also not quite sure if I did this one right. I had thought I need lenz's law but there is no current before entering the field so I just use the induced Voltage? My approach: ## V = \frac {B*A}{t} ## ## IR = \frac {B*A}{t} ## and ## A = v*t...
  42. A

    Permeability of copper in the microwave frequency range

    Relative DC permeability of copper is 1. Conductors are considered dispersive and therefore the permeability should change with frequency. Where can I find data or how can I calculate permeability of copper in Ghz frequency range?
  43. Moara

    Eletromagnetism: Copper Plate on a Spring Oscillating in a Magnetic Field

    Tried to find the resultant force, but I can't see how the magnetic field affects. I used Faraday's law to find the the diferece of potentials in the plate Wich should be B.d.v, where v is the vertical velocity of plate, but there were not given the resistance or resistivity to relate with the...
  44. H

    Current carrying capacity of a copper busbar in an Aircraft

    "The surface of copper naturally oxidises, forming a thin hard layer on the surface which normally prevents further oxidation. " I've seen this in a book, higher level oxygen on busbar, means lower the heat and get away with ease, Doesn't it? So, Can I say a thin hard layer musn't be used?
  45. J

    A Relativistic Effects for Copper and Gold

    Summary: Relativistic effects on the quantum states of electrons in Copper and Gold Hello. I am a new member. I have read that the explanation for the colors of copper(red) and gold(yellow) compared to other metals being silver or grey in color is due to relativistic effects on the valence...
  46. Skyland

    The Possibility of Value in Amalgam Alloys of Gold, Copper and Silver

    Would using mercury to form amalgam alloys combining gold, copper, and silver have any electronic value? Has this amalgam ever been made and tested in conductivity and Malleability? Or would it just be an expensive filling?
  47. L

    I Optimal Copper Pipe Size for Misting System

    I am attaching a standard 5/8" garden hose with approximately 70psi pressure to a copper pipe that is capped on the opposite end with mist nozzles mounted periodically along its length. I want the pressure at each mister to be as similar as possible. The hose attaches at the base, a solid line...
  48. A

    Andrew's Senior Project: Copper Sulfate & Plant Development

    Hello, I'm Andrew and I'm in 12th grade. If you are interested, I would like to share a presentation showing the process, observations, results of an experiment showing the physical effects copper sulfate can have on early plant development. I, with much help from some intelligent members of...