Metals Definition and 340 Threads

A metal (from Greek μέταλλον métallon, "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically malleable (they can be hammered into thin sheets) or ductile (can be drawn into wires). A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.
In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Equally, some materials regarded as metals can become nonmetals. Sodium, for example, becomes a nonmetal at pressure of just under two million times atmospheric pressure.
In chemistry, two elements that would otherwise qualify (in physics) as brittle metals—arsenic and antimony—are commonly instead recognised as metalloids due to their chemistry (predominantly non-metallic for arsenic, and balanced between metallicity and nonmetallicity for antimony). Around 95 of the 118 elements in the periodic table are metals (or are likely to be such). The number is inexact as the boundaries between metals, nonmetals, and metalloids fluctuate slightly due to a lack of universally accepted definitions of the categories involved.
In astrophysics the term "metal" is cast more widely to refer to all chemical elements in a star that are heavier than helium, and not just traditional metals. In this sense the first four "metals" collecting in stellar cores through nucleosynthesis are carbon, nitrogen, oxygen, and neon, all of which are strictly non-metals in chemistry. A star fuses lighter atoms, mostly hydrogen and helium, into heavier atoms over its lifetime. Used in that sense, the metallicity of an astronomical object is the proportion of its matter made up of the heavier chemical elements.Metals, as chemical elements, comprise 25% of the Earth's crust and are present in many aspects of modern life. The strength and resilience of some metals has led to their frequent use in, for example, high-rise building and bridge construction, as well as most vehicles, many home appliances, tools, pipes, and railroad tracks. Precious metals were historically used as coinage, but in the modern era, coinage metals have extended to at least 23 of the chemical elements.The history of refined metals is thought to begin with the use of copper about 11,000 years ago. Gold, silver, iron (as meteoric iron), lead, and brass were likewise in use before the first known appearance of bronze in the 5th millennium BCE. Subsequent developments include the production of early forms of steel; the discovery of sodium—the first light metal—in 1809; the rise of modern alloy steels; and, since the end of World War II, the development of more sophisticated alloys.

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  1. adf89812

    Transition Metal Periodic Trend -- Stackexchange's answer confuses me

    There was a post on stackexchange.com explaining the trend in melting/boiling points of first series transition elements. https://chemistry.stackexchange.com/questions/4766/melting-and-boiling-points-of-transition-elements The specific question was...
  2. adf89812

    Why are metals in aqueous solution basic, and non-metals acidic?

    I heard an explanation about something being a better proton acceptor or lone pair donor but that doesn't make sense. I couldn't explain in in terms of acid-base theory. The hand-waving way I saw it was that metals are less electronegative than non-metals, so in water, they'll donate their...
  3. R

    Compressive strength of aluminum

    Hello, Do all of aluminum bars (or load cells) made from the same type of aluminum (i.e high purity aluminum or different types of aluminum alloys) share the same exact compressive strength or are there variations in compressive strength even among the same type of aluminum like high purity...
  4. Fishworks

    Rank Copper, Brass and Bronze by Thermal Conductivity

    Hi, Can I get help ranking Copper, Brass and Bronze by Thermal Conductivity? This stuff below says Copper is the best Thermal Conductor, and Bronze is the worst. https://en.wikipedia.org/wiki/List_of_thermal_conductivities https://www.engineersedge.com/properties_of_metals.htm...
  5. P

    I How long would a tuning fork vibrate in vacuum?

    [I do not know if this is the right subforum] The answer to the question to the title is: for very long time. However the tuning fork clearly has to stop at some point because some of the energy will turn into heat. However I want to quantify for how long. More specifically I am interested on...
  6. Nadia

    Calculations: Creep of Metals and the Life of a Rod

    I'm sorry I'm uploading lots of images because I don't know how to write equations here. PROBLEM DESCRIPTION I have to solve this problem: Figure P3.6: MY SOLUTION I did this: THE CORRECTION I got this as a correction: - Don't use the middle line in figure P3.6 in my calculations. -...
  7. B

    I Emission of light from incandescence of metals

    a. We know metals emit EM radiation upon heating or electric current. I'd like to understand more fundamentally how this phenomenon takes place, on the basis of the basis of band structure, and which electrons are involved ? b. Classically, charges emit radiation when accelarating or...
  8. L

    Tensile and shear capacity of metals

    Steel and other metals data sheets and mill specs most commonly quote some tensile strength metric, like Proof, Yield or Ultimate Tensile Stress. Less common is the value for shear strength. Often as rule of thumb the allowable shear stress is taken as half the allowable tensile stress but, when...
  9. J

    I Reflectivity of Pure Metals in Vacuum

    All data I see online about reflectivity of metals is about aluminum in the atmosphere meaning oxidized aluminum, but pure aluminum in vacuum in case of the James Webb telescope would also be extremely reflective but building it on Earth means it's going to get oxidized, similarly there are a...
  10. M

    Finding the mass of two metals in an alloy

    I looked for solutions on the internet but all of them had given mass and looked for volume , but that isn't given here. I tried something like subtracting the two weights or trying to find mass from the weight but i can't find the correct awnser
  11. S

    Gallium Alloys and their melting points?

    I am looking to try to create an alloy of gallium (probably with Tin) with a goal of increasing the melting point from 29°C to around 40°C. My current theory is to simply try to average the two melting points out by mass, which my calculations imply means 95% Gallium to 5% tin. my calculation...
  12. H

    Difference between the inelasticity and plasticity of metals

    It is felt that inelasticity can be used interchangeably.
  13. F

    Metals as Infrared Reflectors and their Temperature

    Hello everyone. I have reading about IR radiation, reflectivity, and emissivity of materials. Metals, in general, seem to be excellent reflectors or IR radiation (they are like infrared mirrors. That said, why do they get so hot when they are left in the sun? A metal roof cannot be touched...
  14. R

    Variation of the Speed of Sound in metals under tension

    In a block of metal, each metal has a characteristic speed of sound. When metal is under tension, such as a guitar string, the speed rises as the tension increases. How does the speed vary (in a block say) as a function of tension along each of the three axes? I am assuming that transverse...
  15. R

    Electrostatic Induction in Metals vs Insulators

    If we have a small dielectric sphere and a point charge, they will experience an attractive force due to electrostatic induction. (From the elongation/rotation of charges bound to individual atoms). Likewise, if we have a small metallic sphere and a point charge, they will experience an...
  16. N

    I Blackbody colour of metals versus stars

    Hello. I am new to this forum and joined because I am at home nerding out trying to work something out. Why do white hot metals seem to be much cooler than white hot stars. The attached picture is from Wikipedia relating temperature of a hot metal to its temperature. For example a red giant...
  17. Despot

    Which of the 2 metals is the magnet

    No idea where to start
  18. K

    Different metals in contact with each other

    I learned in school that when two different metals come in contact with each other accelerated corrosion will occur. How about alloy and metal with painted surface? For example, I think that stainless steel is very unreactive / non-reactive. Could it cause any accelerate corrosion to itself or...
  19. Rzbs

    I Why are the d and f orbitals in transition metals considered localized?

    Why d and f orbitals in transition metals considered localize? Is it an experimetal result that d and f orbitals are more near to nuclea than s orbital in transition metals or there is another reason for considering them localized in a solid?
  20. jaumzaum

    I Why is the emissivity of metals low?

    Hello! I am having trouble to understand why the emissivity of polished metals is much lower than if they are not polished. Consider, for example, non-polished aluminium at 300K, which is said to have an emissivity of 0.77. We put it floating in vacuum. There is an energy source near it, and in...
  21. B

    Research question about burning metals and their flashes and colors

    I work for municipality with urban management and i have a interest for the environment, and have become fascinated with metals. Together with a engineer i will be making a report about metal reactions etc. So i would like to get you guys take on these questions that i have in mind for my...
  22. H

    Why Do Ligands Donate Electrons to Electropositive Transition Metals?

    Transition metals, being metals, are electropositive.Ligands like ammonia,oxygen,chlorine etc ,on the other hand,are mostly electronegative(electron loving).How come the Ligands donate electrons to the electro positive(electron hating)transition metals when both have contradictory...
  23. C

    Can molten metals dissolve metal oxides, or vice versa?

    Where a metal melts before its oxide, can that oxide be solvated in the liquid metal? Likewise, if the metal oxide melts at a lower temperature can that solvate the metal? If not generally, can it happen for some metals, or none?
  24. T

    Surface smoothness of a slowly frozen metal droplet

    Would a small (of order 5 microns to 0.5 mm) liquid metal droplet, if cooled slowly away from external perturbations and not in the presence of oxygen, retain its highly smooth and polished surface as it froze? What phenomena would influence the surface roughness? I assume that simple density...
  25. J

    Detecting metals with a capacitance multimeter and a circuit

    A makeshift metal detector can be made if you have an accurate INDUCTANCE meter and a coil of a large diameter. Instead, I've got a capacitance meter, this one: http://www.pw-electronics.co.uk/DMM.pdf How can a little circuit be added (like a capacitor with a resistor in series or in parallel...
  26. S

    Producing other metals with thermite reactions

    Hello all, I am curious as to whether it is possible to create aluminium from a thermite reaction. Thermite, as standard, uses aluminium and iron oxide, which react together when burnt to create a blob of molten iron. I would like to achieve a similar result, but with a blob of molten...
  27. S

    Do all transition metals have the n2 and (n-1)d orbitals?

    Does all transition metals have their n2 and ( n-1)d orbitals as valence electrons? I have been scouring the internet to the answer of this question but have mixed results. Iron has an electron configuration of: 1s2,2s2,2p6,3s2,3p6,4s2,3d6 Aparantly it has 8 valence electrons because 4s2 + 3d6 =...
  28. jedishrfu

    Universal Quantum Phenomena found in Strange Metals

    A recent paper in Nature describes a new phenomena found in superconducting materials: https://www.nature.com/articles/s41567-018-0334-2 Quanta magazine wrote about it here: https://www.quantamagazine.org/universal-quantum-phenomenon-found-in-superconductors-20181119/
  29. M

    Force between two different metals?

    Hi everyone... I work in a rolling mill that produces train rail tracks. But I'm experiencing some problems. The guards I use keep breaking. So here is the scinario. The rail we make is 40kg per meter. With a total length of around 65m. When it goes thru the mill pressure is applied to it in...
  30. DLeuPel

    Can Mu metals redirect a magnetic field?

    I am trying to find a way to decrease the force between two magnets by putting a physical barrier in the middle of them. I’ve reasearched and found that Mu metals redirect the flux of the magnetic fields so those two magnets shouldn’t have any noticeable attraction between them. Of course...
  31. E

    A Electron spin resonance in metals

    In practice, ESR/EPR seems to concern only unpaired electrons in the outer layers of organic radicals or complexes. But what about the free electrons of metals? Does it also give rise to a signal? I can't find any information on the web. Thanks
  32. L

    Which of these metals provide magnetic shielding?

    Homework Statement This a question from an olevel paper and the marking scheme says B I don't understand why Homework Equations None a theory question The Attempt at a Solution Aluminum and copper has less magnetic property while iron is good magnetic material. I cannot understand why the...
  33. A

    Determine acclimation time for metals

    A little background: Inspection room is kept at 20 C +/-2 C. Temperature gauge is accurate to +/-.5 C. Outside ambient temperature where parts are kept can vary from 5 C to 38 C. One part in particular is a rotor made of 4340 steel, ~2350mm long, average diameter of 115mm, and weighs ~ 650lbs...
  34. E

    Different metals and their compounds' reaction to Microwaves

    Does anyone know of any studies into exactly how much various metals reflect or absorb microwaves with relationship to the microwaves wavelength and ideally theyt compounds too?
  35. D

    Choosing the Best Metal for Surgical Tools: Steel or Titanium?

    Hello Colleagues, I have a project for medical application. It has a cutting part for precise incisions. It should have excellent notch tensile strength and resistance to pitting corrosion. Obviousely this should be surgical steel or titanium. What would you take?
  36. harambe

    I How Do Metals Reflect Light Across Different Frequencies?

    https://eng.libretexts.org/Core/Materials_Science/Optical_Properties/Metallic_Reflection According to this article,metals are good reflectors at low frequencies.What about at high frequencies like visible or UV spectrum?Will this show deviation
  37. lc99

    Clarification About Heating Metals (basics)

    Homework Statement So i have a few scenerios on my physics prelab that I want to clear up and understand. 1) What happens to the temperature when you heat up a solid metal much below its melting point? 2) What about when the solid metal starts to melt (and you are heating it still)? 3) What...
  38. amjad-sh

    Spin-orbit coupling at the interface between two metals

    sorry I am going slightly off the topic. <<Moderator's note: split off from this thread.>> I asked this question because I'm studying a paper concerning the presence of spin orbit coupling at the interface between two metals. This is the part of the paper I'm studying: "Our aim is to...
  39. M

    Why do hot metals emit radiation - atom vibrations?

    Why does a tungsten filament light bulb (or any heated metal for that matter) emit EM radiation (both visible and infrared) - is the EM radiation due to vibration of molecules or electron excitation?
  40. C

    Does electron gas in metals experience viscosity?

    Does electron gas in metals experience viscosity? Also, does highly charged plasma experience viscosity?
  41. ISamson

    B Chemical study of an old, metal-rich globular cluster

    Regarding a recent article from phys.org , Chilean researchers have conducted a study of an old, metal-rich cluster, NGC 5927. Interesting results are the abundance of many metals, which include sodium, aluminium, iron, oxygen and some heavy metals such as yttrium and zirconium. Thank you.
  42. ORF

    How surface tension is measured for molten metals?

    Hello How the surface tension is measured for molten metals? I have heard about the sessile drop, but it seems to be a very inaccurate method... Thank you for your time. Regards.
  43. M

    A Can Relative Permittivity of Aluminum Be Calculated from Its Plasma Frequency?

    Consider a metal such as Al. How do we look up or determine the relative permittivity of the metal? Suppose we have some known incident frequency, say about c/500nm for visible light. We can look up the bulk plasma frequency (3.7 PHz for Al), can it be calculated from that? For context, what I...
  44. shihab-kol

    Understanding Metal's Lustre: Why Does Specular Reflection Occur?

    What gives metals their Lustre? One of my books(living science chemistry by arun syamal) says that the electrons achieve a higher energy state by absorbing energy and come back to their ground state by emitting it of which light is a part but my teacher tells that it is due to the crystalline...
  45. shishi

    Negative permittivity of metals – light-trapping and plasmon

    Negative permittivity of metals – The effect of light-trapping via plasmonics I’m trying to understand the effect of light-trapping by plasmonics (for example - Localized Surface Plasmon Resonance, Surface Plasmon Polariton, Scattered Plasmons), and how negative permittivity related to that...
  46. D

    I Exploring the Effects of Cold Welding in Space

    I've read that when two pieces of the same kind of metal touch in space, they will fuse because there is no way for the electrons to "know" that they are in different pieces of metal. What would happen if two different metals were to touch in space? Would electrons still flow freely between...
  47. M

    What happens to the metals thrown into the soil?

    I wonder about what will happen to the metals and alloys such as iron, lead, argent, gold, mercury, cambium, steel, nickel, bronze when thrown into the soil. Can bacteria decompose them such as organic components? They were already under the soil before men picked them out. This is a very hard...
  48. J

    How Much Power Is Needed to Melt Lead?

    This question is purely theoretical, so don't worry about safety or doability. Is there a way of calculating how many watts it takes to heat different metals? To be specific, how many amps and bolts it would take to get lead to its melting point. Thanks in advance.
  49. Carlos

    Heat capacity as a function of T under 298 K for metals

    The heat capacity equation Cp for copper as a function of temperature (Shomate equation) for the solid phase is defined for the range of 298-1358 K in the Nist Webbook and in many books. http://webbook.nist.gov/cgi/inchi?ID=C7440508&Mask=2#Thermo-Condensed And I need to calculate the heat...
  50. E

    What is the Young's Modulus of Aluminum, Steel, and Brass?

    Homework Statement hi guys I am conducting an experiment for my coursework in physics and i have come across a bit of a problem. i am trying to calculate the youngs modulus of 3 different metals Aluminium steel and brass. To calculate the modulus of the material i am using a chart of Mass k/g...
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