What is Mercury: Definition and 255 Discussions

Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum ( hy-DRAR-jər-əm). A heavy, silvery d-block element, mercury is the only metallic element that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature.
Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide.
Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alternatives such as alcohol- or galinstan-filled glass thermometers and thermistor- or infrared-based electronic instruments. Likewise, mechanical pressure gauges and electronic strain gauge sensors have replaced mercury sphygmomanometers.
Mercury remains in use in scientific research applications and in amalgam for dental restoration in some locales. It is also used in fluorescent lighting. Electricity passed through mercury vapor in a fluorescent lamp produces short-wave ultraviolet light, which then causes the phosphor in the tube to fluoresce, making visible light.
Mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), by inhalation of mercury vapor, or by ingesting any form of mercury.

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  1. djanni_unchained

    A How do we interpret measurements of Mercury's position?

    When scientists measured the position of Mercury in the 18th century, they interpreted the results assuming a Euclidean background, because they did not know general relativity. So they measured r and φ in fuction of time attributing to these coordinates an Euclidean meaning, that is, assuming...
  2. S

    A Atmospheric Density Required for Mercury´s Polar Regions to be Warm?

    Venus has a dense atmosphere (about 90 bar). Although Venus has a low axial inclination and the poles of Venus are therefore always in twilight, the day side atmosphere heats to about +460 C and the heat transport at the 90 bar atmosphere is so efficient that the poles are no more than 10 C...
  3. A

    B BepiColombo Mission to Mercury

    Will the 2025 BepiColumbo mission be able to detect any indications of potential past or current microbial life on Mercury?
  4. gary808

    I Mercury as a plasma at 150 Kelvin

    I was reading up on a theoretical engine employing the following, “Mercury plasma pressurized at 250k atmospheres, at a temperature of 150 degrees kelvin (-123° C), and swirled within its accelerator to 50k RPM.” Does pressurizing mercury so much somehow allow a plasma to form at such sub-zero...
  5. J

    Specific volume and enthelpy of mercury

    I have been away from thermodynamics for a while, and there is a young mechanical engineering student who asked my help in solving the question. For the life of me I am unable to solve this problem and I am at my wit's end. I believe I can solve the problem if some pointers are provided. Also...
  6. R

    Would anyone be able to help me regarding mercury?

    Hello all, Would anyone be able to help me with a few different questions I have about mercury? I'm looking at the feasibility of purchasing a small amount of elemental mercury and would appreciate if anyone could give me some direction. On the internet, there seems to be a range of widely...
  7. H

    B Explaining Perihelion Shift of Mercury in GR Theory

    Recently, when reading an entry about Mercury's perihelion shift, someone mentioned a "hand-wavy" explanation as to why GR predicts the orbit so precisely. I was wondering if there was some elementary way to expound on what he was saying. Fundamentally, the comment said something to the effect...
  8. P

    Gas in mercury manometer, finding its normal volume

    Some notation: - the difference between the heights of mercury, which is effectively the height of the mercury in the open end of the tube is ##h_{diff}## - the volume of gas inside the sealed off end is ##V_{inside}## - the volume of gas when let outside, "normal volume", is ##V_{outside}## -...
  9. P

    Mercury barometer with a small amount of air

    $$\rho_{Hg} gh_{actual} = \rho_{Hg} gh_{measured} + \rho_{air} gh_{air}$$ Note: by "actual", I mean "theoretical", i.e. what the barometer would measure were there no air inside it. By "measured" I mean "as measured by the faulty barometer, i.e. with some air introduced". I believe this...
  10. N

    I UV mercury lamps: Changing the 185nm vs 253.7nm ratio

    According to Wikipedia, (citation needed) https://en.wikipedia.org/wiki/Ultraviolet What would alter this proportion of emitted radiation to favor more 185nm radiation? Preferably not with a filter that filters out 253.7nm (mathematically would also increase the ratio of radiance of...
  11. J

    Heat related problem -- Mercury solidifying liberates some energy

    I have used the heat equation and am not able to get the initial heat. This is what I have so far: 81060 = 7 * 140 * (change in temp) - (7 * 11300) + 7 * 140 ( change in temp) I found the change in temp to be 81.71K. But that does not help me with the initial temperature!
  12. M

    I Precession of Mercury: Adaptation for Observers

    For the observation of the gravitational redshift one needs an adaptation of the GTR of the object (related to the Sun´s gravity) and the observer (related to the Earth’s gravity). I assume that the situation is similar for the observation of the precession of Mercury, another experiment...
  13. cianfa72

    I Mercury Perihelion Precession: Analytic Derivation

    HI, I'm curios about the analytic derivation of Mercury perihelion precession starting from EFE - Einstein Field Equation (or simply just from Schwarzschild solution of the EFE). Can you advise me about some source or online material to learn it ? Thanks.
  14. B

    Determine the change in elevation of mercury in this manometer

    Having some trouble in answering this question What I have done so far is calculate the initial pressure difference, then used that to find the new pressure difference when pipe's A pressure increases by 34.4 kPa Not too sure of where to carry on from here? All I know is that if pipe A is...
  15. ORF

    Why the alcohol thermometer is less precise than the mercury one?

    Hi, Why the alcohol thermometer is less precise than the mercury one? If I remember correctly, it is because the thermal expansion coefficient of alcohol is not constant, but I am not sure. Thank you for your time. Regards, ORF
  16. R

    I Confused about Mercury Barometers

    The figure shows two mercury barometers. 1. My first question is why specifically does it have mercury? Is the mercury a gas or a liquid? Why can we not just use water? Does the pressure of the liquid have to be less than that of the atmosphere for this to work? 2. The book says for a given...
  17. S

    Mercury vapor from blood pressure devices

    I came across some articles about the health hazard from broken mercury-based sphygmomanometers. This led me to think about vapor leakage from good devices during normal operation. The top of the glass tube is at ambient atmospheric pressure. There is supposed to be a membrane at the top that...
  18. H

    Relativistic effect in mercury

    How come mercury qualify as a metal, since the 6 s electrons are attracted by the nucleus so strongly because of relativistic effects and unlike other metals there is no cloud of electrons?. Because of this mercury is not a good conductor of electricity unlike other metals
  19. Andy Resnick

    Stargazing Witness the Transit of Mercury: Nov 11, 2019

    For those so inclined: https://Earth'sky.org/tonight/transit-of-mercury-on-november-11-2019
  20. ValeForce46

    A glass tube filled with mercury

    I guess I have to find out something when the tube is on the horizontal. What force should I consider? Is the pressure of the air inside still ##p_{atm}##? When it is on the vertical, the equation is something like this? ##P_{Hg}+p_{atm}*A=p_{atm}*A+ρ_{air}*A*(l_1-l_1')*g## with...
  21. A

    Mercury Seal Gap Size: Is it Possible?

    I am wondering about the physical properties of mercury. I know that different materials have different density and ability to penetrate small openings. I wonder if I have a small container of mercury, say about 100 grams or less, and there is a small flat opening at the bottom of such container...
  22. A

    Mercury adhesion and wetting to plastics/polycarbonate/glass

    Hi, I am starting to make some experiments with my project and part of it involves developing a small MHD system. Now for test purposes and ease of manufacturing I have decided I want to use some clear see through plastic which would help me see whether my experiment is working as planned. My...
  23. Physics345

    Question regarding the differential height of mercury in a manometer

    Given: ##y_{2} - y_{1}= 0.2m## ##Q= 1.5\frac{m^{3}}{min}## ##Q= 0.025\frac{m^{3}}{s}## After conversion ##D_{1}= 0.2m## After conversion ##D_{2}= 0.1m## After conversion ##r_{1}= 0.1m## ##r_{2}= 0.05m## ##p_{1} - p_{2} = \frac{1}{2}P(v_{2}^{2}-v_{1}^{2}) + Pg(y_{2}-y_{1})## Calculating...
  24. F

    B How are the mercury atoms in a fluorescent lamp ionised?

    I think I vaguely understand how it works but not completely. So far, I understand that fluorescent lamps have an electrode at both ends and are filled with an unreactive, low-pressure gas such as mercury. When the current passes through, the electrons are accelerated and they collide with the...
  25. K

    Piezoelectric Quartz with Pressurized Mercury Vortex

    I am curious if it would be possible to put a quartz crystal at the bottom of strong cylinder vial with half the crystal hanging out the bottom (but sealed) and have mercury on top of it and then pressurized if it would create a constant vortex? If the mechanical force of the pressure from the...
  26. G

    I Why does a mercury Franck-Hertz tube produce visible light?

    Hi. I've recently conducted a Franck-Hertz experiment with mercury. I was able to see bluish glowing regions just as here: However, theory predicts 254 nm, which is far below visible. Are there other energy levels at play here? Wouldn't that mess up the 4.9-V-spaces of the drops in the current...
  27. S

    I Why do transits of Mercury only occur in May & November?

    I was reading about the upcoming transit in May, 2019, and this fact seems quite peculiar. Is there some type of resonance?
  28. P

    How the forces on a drop of water versus mercury on a glass slide influence the shape?

    I am trying to understand how fluids form particular shapes when put on a solid. In the two figures,what are we taking as a system for the forces? How the resultant of the forces influences the shape of the different fluids?
  29. W

    I The light from Mercury, the Sun's corona and gravity

    The question is: The General Relativity Ideas were confirmed by the position of Mercury by Eddington. How could they be certain that the light deviation was due to gravity rather than the lens effect the Sun's corona may have had? What process was used,if any,to remove the effect of the...
  30. A

    B Why does mercury rise in a glass capillary tube despite its strong cohesion?

    It's a question which come into my mind after reading related notes now and again and I can't think of plausible response to it. Given Statements: We have a container filled with mercury and a glass capillary tube placed in it . As tube's diameter become smaller mercury's height in tube will get...
  31. M

    What would happen to a blob of mercury in space?

    How long would it take for a blob of mercury (the size of a marble or so) to freeze in space? I'd emagine it would have to boil in some way first, and that would send pieces of it flying around, but the surface tension of mercury is much greater than that of water, or urine (as we'd seen...
  32. Y

    Push Mercury out to Venus' orbit?

    So it would be cooler and mine-able? Given unlimited tech and wealth in a fictional setting.
  33. klotza

    Insights Either the Sun Is Getting Smaller or Gravity Is Getting Weaker

    Greg Bernhardt submitted a new PF Insights post Either the Sun Is Getting Smaller or Gravity Is Getting Weaker Continue reading the Original PF Insights Post.
  34. Richie Smash

    Pressures of a gas in cm of mercury

    Homework Statement Hello, I will post a picture here of a question. It states, a column of air is trapped by 5cm of mercury as shown. What is the pressure in cm of mercury in the gas in each case? Homework Equations Pressure= h*g*rho The Attempt at a Solution I would use that equation but...
  35. I

    Hydrostatics, Length of a mercury column

    Homework Statement What will be the length of mercury column in a barometer tube, when the atmospheric pressure is 75 cm of mercury and the tube is inclined at an angle of 60° with the horizontal direction? Homework Equations Pascal's Law The Attempt at a Solution l ⋅ sinϑ = h l = h / sinϑ l...
  36. B

    I Hydrogen plasma compression with liquid Mercury piston

    I'm working on a thought experiment. I want to know how much of the kinetic energy from a liquid mercury piston will be converted into work done on the hydrogen plasma in the form of compression, and how much work will be done on the piston in the form of compression. Note: assume piston walls...
  37. S

    Is Mercury a Danger to Your Health?

    I have heard people claim that if you stick your hand in mercury, if you do not have any injuries on you, you will not be harmed as long as you have good ventilation. I have also heard people claim that mercury is basically a manifestation of death itself. So how dangerous truly is mercury? By...
  38. D

    Would HE light applied to mercury vapor produce electricity?

    I'm likely going to have a ton of questions in the following weeks about a wide range of particle physics etc. If (electricity X mercury vapor) = light, then multiplication being transitive, (light X mercury vapor) = electricity. Can someone inform? I've found only mercury vapor as a metallic...
  39. B

    B Removing a proton from mercury

    Why are there no gold companies that produce gold by removing a proton from mercury? Is it because mercury is expensive or lack of facilities to remove the proton. Given a lot of budget (like billions).. what would it take to remove a proton from mercury to produce gold?
  40. C

    Interference of light, emission spectroscopy prac. report

    Ok, so I've got a practical report due tomorrow and I just wanted to clarify a few things. A bit of background knowledge first. The practical involved taking angular measurements for the emission lines of the Mercury spectrum using the apparatus, a spectrometer and a Mercury spectral tube...
  41. Z

    Investigation about the emission spectrum of Mercury

    Homework Statement For our investigation, we used a diffraction grating spectrometer to observe the emission spectrum of mercury. We conducted the experiment in a pitch black room to avoid any unwanted light pollution, etc. Whilst conducting the experiment we observed a number of 'faint' lines...
  42. G

    I Mercury's precession due to other planets

    Hi. I'm interested in how physicists in the mid-19th century such as Urbain Le Verrier were able to compute the gravitational influences of the other planets on the apsidal precession of Mercury's orbit, finding that they can only explain about 531" (per century!), not the observed 574". This...
  43. Marcus95

    Biconvex Lens Floating on Mercury

    Homework Statement A thin bi-convex lens with refractive index n has spherical surfaces with equal radii of curvature r and measured focal length f. The lens floats horizontally on the surface of liquid mercury so that its lower surface effectively becomes a spherical mirror. A point object on...
  44. S

    Why is it that Mercury rotates at a faster rate than say Pluto

    If dark matter is responsible for the inner stars within a galaxy rotating at the same rate as the outer stars, then why is it that murcury rotates at a faster rate than say pluto.This posses the question why are we searching for evidence of dark matter deep in the Earth when there seems to be...
  45. G

    Understanding Mercury and Thermometer: The Science Behind Temperature Expansion

    Why does mercury in a thermometer expands when we increase the temperature but it doesn't go down after cooling? Why does it just stay there?
  46. M

    Atmospheric Pressure: Solving with a Mercury Barometer

    Homework Statement A mercury barometer located in a room at 25°C has a height of 750 mm. What is the atmospheric pressure in kPa? Homework Equations Patm = ρ*g*H0 The Attempt at a Solution [/B] My question pertains to the units and how it ends up as kPa in the book. I have no problem with...
  47. U

    I Mercury Precession and the Hypothetical Oblate Sun Model

    I have a student who thinks he is smarter than me. When we calculate the precession the classical way we also account for the supposed oblate sun. If we model sun's oblateness by splitting the mass of the Sun into 2 masses and separate them by distance s, then the acceleration we get on point...
  48. P

    I Why is Mercury Visible at Night?

    Hello, I have been doing extensive research into planetary positions and distances from the sun. When viewing the sky for planets it has been noticed that Mercury is in the night sky. Mercury is at 36million miles from the Sun. Earth is 93million miles from the Sun. How can the planet Mercury be...