What is Hydrogen: Definition and 999 Discussions

Hydrogen is the chemical element with the symbol H and atomic number 1. With a standard atomic weight of 1.008, hydrogen is the lightest element in the periodic table. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass. Non-remnant stars are mainly composed of hydrogen in the plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol 1H), has one proton and no neutrons.
The universal emergence of atomic hydrogen first occurred during the recombination epoch (Big Bang). At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2. Since hydrogen readily forms covalent compounds with most nonmetallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions because most acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H+. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics.
Hydrogen gas was first artificially produced in the early 16th century by the reaction of acids on metals. In 1766–81, Henry Cavendish was the first to recognize that hydrogen gas was a discrete substance, and that it produces water when burned, the property for which it was later named: in Greek, hydrogen means "water-former".
Industrial production is mainly from steam reforming natural gas, and less often from more energy-intensive methods such as the electrolysis of water. Most hydrogen is used near the site of its production, the two largest uses being fossil fuel processing (e.g., hydrocracking) and ammonia production, mostly for the fertilizer market. Hydrogen is problematic in metallurgy because it can embrittle many metals, complicating the design of pipelines and storage tanks.

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  1. Entropix

    I Hydrogen balloon experiment -- How high can it rise?

    If we launch a hydrogen balloon from the Earth surface (let's say it has a 2 meter radius) and assuming it's strong enough so it doesn't pop/disintegrate (it's made out of carbon nano-tubes). Where this balloon will stop? I'm more interested in the exact altitude it reaches or if it will keep...
  2. M

    Seeking books to help me understand the structure of the Hydrogen Atom

    TL;DR Summary: How to learn about the Hydrogen Atom from Level 2 OU Degree I am copleting the second year of the OU physics degree and "understand" what is taught about the Hydrogen atom there, energy levels et al. I am not yet competent in calculus here. I seek a means, buy a book....view...
  3. P

    I Emission Spectrum & Energy: Exciting Hydrogen Vapor

    By exciting hydrogen vapors with heat or electrical discharges, it is possible to obtain the element's emission spectrum. In it, as can be seen, appear multiple wavelengths, each corresponding to a particular orbital electronic transition. From this it can, therefore, be inferred that heat and...
  4. ergospherical

    I Instability of hydrogen ground state if the time-reversal operator is unitary

    Apparently if we try to represent the time reversal operator by a unitary operator ##T## satisfying ##U(t)T = TU(-t)##, then the ground state of hydrogen (the hamiltonian of which is time-reversal invariant) is unstable. But if ##T## is anti-unitary (i.e. ##\langle a | T^{\dagger} T | b \rangle...
  5. Y

    Why are Hydrogen cars not popular?

    I have no idea about this, I hope it's not a controversial subject. I know it's been around, it's not new. All I know is H2 is dangerous. Other than that, I have no idea. Just want to hear from people with scientific knowledge. Thanks
  6. uxioq99

    The Energy Expectation Value for a Moving Hydrogen Atom

    ##\begin{align} \langle E \rangle &= \int_{\mathbb R^3} \int_{\mathbb R^3} \int_{\mathbb R^3} \int_{\mathbb R^3} g^\dagger (\tilde K) g(K) |\psi_0(x)|^2 \left(E_0 +\frac{\hbar^2 |K|^2}{2m}\right) e^{i(K-\tilde K)\cdot X -\frac{i}{\hbar} \left(\frac{\hbar^2 |K|^2}{2m}-\frac{\hbar^2...
  7. topsquark

    A Solving the Radial Equation for the Dirac Hydrogen Atom Solution

    I'm going to be a bit sketchy here, at least to start with. If you want me to show you exactly where I am I might post a pdf, if that's okay. (Only because it will simplify coding several pages of LaTeX.) Briefly, what I'm trying to do is take this system of equations: ##F^{ \prime } +...
  8. S

    I Are the proton and electron quantum entangled in the hydrogen atom?

    The proton and electron are described by separate wavefunctions. When they come together in the hydrogen atom are they quantum entangled and have a joint wavefunction.
  9. J

    I Two hydrogen atoms and Pauli's exclusion principle

    Hello, I recently came across the following (apparent, I hope) paradox: suppose we have two H atoms. Now, a hydrogen atom is made up of one proton and one electron (fermions), so it is a boson. Then one could have two hydrogen atoms which are in the exact same state (including position). This...
  10. P

    Solubility depends on polarity or on the number of hydrogen bonds?

    Does solubility depend on the polarity of the molecule or on the number of hydrogen bonds that are formed with water? For example: CF4 can form hydrogen bonds, but it's not polar. Glucose Is Polar e can form hydrogen bonds. How can I predict solubility? Thanks
  11. M

    Is there a way to use the hydrogen in the human body?

    I recently read that there is enough hydrogen in the human body to lift 195 lbs off the ground. I know this sounds super-silly but if we ever develop nanites; could they manipulate the hydrogen and allow us to float?
  12. abolfazlghasemi

    Hydrogen dew point in power generators

    Large power generators (for example 200 MW) are cooled by H2 in gas form. H2 temperature is +45 to +75 "C. So why hydrogen dew point is important in generator while the lowest hydrogen temperature is 45 "C? And in some Power Stations is monitored online... Thanks, a lot
  13. C

    I Is the magnetic moment of a hydrogen atom not equal to Bohr's magneton?

    Can you cite experiments where, in some excited states of a hydrogen atom, magnetic moment significantly differs from Bohr's magneton was detected? Correction for magnetic moment of nucleus is insignificant. Only experimental data, not theoretical forecasts. Starting from the experiments of...
  14. S

    Tca mixed with hydrogen peroxide

    A company has made a skin peel made with 33% tca 5% kojic acid and 62% hydrogen peroxide. But you don’t peel. I want to make my own since I can’t afford the product. How do I do it
  15. KingoftheChaosEmpire

    "Rigid airship" using low density hydrogen (LDH) inflation

    I know now that making a full on vacuum airship is unfeasible for it's compressive properties. So why not just make a rigid airship that is evacuated enough that the hydrogen is no longer significantly dangerous to it's surroundings, using say 25-30% density of neutral hydrogen? What's the...
  16. snoopies622

    I Why is the SE better than the KG equation for a hydrogen atom?

    my premises: — one can arrive at the Klein-Gordon equation by applying quantum mechanical operators to the special relativity dynamics equation E^2 = (mc^2)^2 + (pc)^2. — Schrodinger arrived at this equation, but rejected it because it didn't correctly explain the behavior of an electron in a...
  17. S

    Interpreting the various tracks in a hydrogen bubble chamber

    (a) I don't know how to identify which one is the anti-proton track. The anti-proton hits proton at point in the figure where all the lines are coming together but how to identify which one is anti-proton? Do I need to know a certain rule regarding the color of each particle? Thanks
  18. O

    I Why are the spectral lines weak in my hydrogen Geissler tube?

    Using a hand spectroscope, I looked at the spectrum of two geissler tubes, helium and hydrogen. The helium spectrum is what I expected, dominated by five distinct lines. The hydrogen spectrum, however, is somewhat disappointing. It is dominated by an almost continuous spectrum, it is not evident...
  19. D

    Looking for information on hydrogen thyrator

    Greetings, gentlemen. I have come into possession of what I have been told is a hydrogen thyrator. Of course I have done the requisite Googling, but do any of you old EEs have any insight on the item? Original application, general manufacture date, usage today, value, precautions in handling...
  20. P

    I Wavefunction of ionized hydrogen electron

    At what point does the electron become ionized in the hydrogen atom solution
  21. J

    Degradation of Accelerated Hydrogen Peroxide

    I started fostering kittens during the pandemic. A very useful veterinary disinfectant that I make use of is accelerated hydrogen peroxide. It is sold under the brand name "Rescue". In its concentrated form it has a shelf life of about 2 years. It's kind of expensive. Typically a dilution of a...
  22. S

    I Partition function rotation

    Hey, I have a question about proving Saha's equation for ionizing hydrogen atoms. The formula is \frac{P_{p}}{P_{H}} = \frac{k_{B} T}{P_{e}} \left(\frac{2\pi m_{e} k_{B}T}{h^2} \right)^{\frac{3}{2}}e^{\frac{-I}{k_{B} T}} with P_{p} pressure proton's, P_{H} pressure hydrogen atoms, m_{e}...
  23. M

    Researching Turboprops: Fuel Comparison of Hydrogen, Methanol, & Jet A1

    Hello I'm trying to get some good reference material so I can do a literature review on Turboprops and a comparison of PSFC of Hydrogen/Methanol/Jet A1 fuels for turboprops. If anyone knows any good source material for this please let me know as I have struggled to find anything. Regards, Michael
  24. R

    Quantum Books recommendation covering the Hydrogen atom and Kepler's laws (separately)

    Hi, I have an interview for masters degree program in 2 weeks and they asked to study two subjects thoroughly, first being Hydrogen atom and second being Kepler's laws. anyone recommends one book about each subject with advanced level questions that would help me understand the subjects to a...
  25. Salmone

    I Matrix element in problem with hydrogen atom

    I have a problem in calculate a matrix element in a problem with hydrogen atom. I have an hydrogen atom and Hamiltonian eigenstates ##|n,l,m>## where ##n## are energy quantum numbers, ##l## are ##L^2## quantum numbers and ##m## are ##L_z## quantum numbers, I have to calculate the matrix element...
  26. guyvsdcsniper

    States in the Hydrogen Atom that are not allowed

    I am a little lost on how to approach this problem. What I know is the following: The r vector is in terms of x y and z hat. I know my two l=0 states can be the 1s and 2s normalized wave function for Hydrogen. Should I be integrating over dxdydz?
  27. guyvsdcsniper

    Probability of electron in hydrogen nucleus for 1s and 2s wave-functions

    For this problem, Is it as simple as using the probability density function, P = Ψ2 and plugging in the radius value given to me? So essentially I am just squaring the wave function and plugging in?
  28. Mr X

    B Hydrogen spectrum and orbits

    Since hydrogen atom has only one orbit, how does the hydrogen line spectrum work? I saw somewhere, that infinite orbits(n) are possible, but wouldn't having too much energy end up causing the electron to break free from the nucleus and thus ending up as a free electron? So when exactly does...
  29. BenDover

    Why does combining Hydrogen, Oxygen and Sulphur produce a liquid?

    Hydrogen is a gas, sulfur is a solid, oxygen is a gas, why does combining them to produce sulfuric acid produce a liquid?
  30. Mr_Allod

    Probability of finding a pion in a small volume of pionic hydrogen

    Hello, I am trying to figure out the right way to approach this. First of all, other than the different Bohr radius value, does the change to a negative pion make any other difference to calculating the probability? Also what would be the correct way to apply the "small volume"? What I'm...
  31. agnimusayoti

    Average Separation between molecules in hydrogen at STP (Alonso Finn Problem)

    The relative density data: $${\rho_{H_{2},H_{2}O}}=\frac{\rho_{H_{2}}}{\rho_{H_{2}O}}=8.988\times10^{-5}$$ With avogadro number, thus I can obtain number of molecules per 1 ##m^3## of Hydrogen gas, that is: $$N = \frac{{{\rho_{H_{2},H_{2}O}}}\times{\rho_{H_{2}O}}}{M_{r}}\times{N_{A}} $$ thus, I...
  32. Twigg

    I Does putting a hydrogen atom in a box mix angular momentum states?

    If you put a hydrogen atom in a box (##\psi=0## on the walls of the box), spherical symmetry will be broken so ##n##,##l##,##m_l## are no longer guaranteed to be good quantum numbers. In general, the new solutions will be a linear combination of all the ##|n,l,m_l\rangle## states. I know that...
  33. user366312

    How can I calculate hydrogen bonds in a specific direction w.r.t. a C-

    I need to calculate H-bonds in a specific direction of a C-alpha atom of a protein. And, I need to calculate that from a PDB file. Can anyone give me a general guideline/direction/idea regarding how to do that? N.B. I need to write a python program.
  34. A

    Powerline electrolysis hydrogen production

    Hydrogen production consumes a lot of energy because one is running current through water in order to produce hydrogen. Why can't we use current that already runs in powerlines for example like HVDC and create a series electrolysis apparatus. Water electrolysis needs a minimum voltage...
  35. Mayhem

    Zero-point energy of diatomic hydrogen (particle in a box)

    If we take ##H_2## as a "particle" in a box, can the zero-point energy of the overall molecule be calculated as the sum of the zero-point energies of all particles in ##H_2##? That is $$E_ {1,H_2}=\frac{2h^2}{8m_{\mathrm{H^+}}L^2} + \frac{2h^2}{8m_{\mathrm{e^-}}L^2}=...
  36. M

    I Escape of Hydrogen from the Earth's Atmosphere

    Hi ! I ask you two questions: 1- If hydrogen escapes from the Earth's atmosphere as it happens, because if there are anaerobic bacteria that produce hydrogen naturally among some other living beings, because among the thousands and millions of years that life has been on earth, hydrogen was...
  37. Astronuc

    Mining waste for cheaper hydrogen fuel production

  38. T

    A Relation of ionisation voltage vs. pressure for hydrogen

    Suppose we have specific amount of hydrogen gas enclosed inside a metallic chamber and that is connected to a very high positive voltage source. As the voltage is positive and that's so high that all the molecules inside the chamber lost their electrons and there is nothing but a nuclei gas is...
  39. H

    Overlap integral of hydrogen molecule

    Hi! Some help with this problem would be much appreciated. The overlap integral is defined as ##S = \int \phi_A (\mathbf{r}_A) \phi_B (\mathbf{r}_B) \,d\mathbf{r}##. For the two orbitals, I have that $$\phi_A = \frac{1}{\sqrt{\pi}} \Big( \frac{1}{a_0} \Big)^{3/2} e^{-r_A / a_0}$$ for the 1s...
  40. M

    I Dirac equation in the hydrogen atom

    Hello! I went over a calculation of the hydrogen wavefunction using Dirac equation (this one) and I am a bit confused by the angular part. The final result for the wavefunction based on that derivation is this: $$ \begin{pmatrix} if(r) Y_{j l_A}^{m_j} \\ -g(r)...
  41. seandepagnier

    Hydrogen combustion catalyst

    I am interested in build a hydrogen stove for cooking and wish to use a catalytic stove. I cannot find much information about this anywhere, but only that nickel can be used for hydrogen rather than platinum. 1) Can I just use stainless scotch brite scrub pad as catalyst assuming it...
  42. H

    Electron wavefunction in hydrogen

    Hi. I would love if someone could check my solution since me and the answer sheet I found online don't agree. The probability is given by the triple integral \begin{align*} \int_0^{r_b} \int_0^{2\pi} \int_0^\pi |\psi (r)|^2 r^2 \sin{\theta} \,d\theta \,d\phi \,dr &= \frac{1}{\pi...
  43. skywalker

    I More info on HT/HD shielding constants?

    I was wondering how they measured or calculated these differences? I don't know what they refer to, but assume theyre scattering Hydrogen with Tritium or Deuterium to measure the difference of something. https://physics.nist.gov/cgi-bin/cuu/Results?search_for=shielding+difference
  44. Ranku

    I Rotation curve with neutral hydrogen and dark matter

    Flat rotation curve in galaxies is determined by observing neutral hydrogen which is co-distributed with dark matter. What is the rotation curve profile of neutral hydrogen in galaxies where there is less dark matter?
  45. O

    I General solution of the hydrogen atom Schrödinger equation

    Hello everyone! I have two questions which had bothered me for quite some time. I am sorry if they are rather trivial. The first is about the general solution of the hydrogen atom schrödinger-equation: We learned in our quantum mechanics class that the general solution of every quantum system...
  46. P

    B Can a hydrogen atom become a neutron?

    I read this from Nasa's website: "Within the first second after the Big Bang, the temperature had fallen considerably, but was still very hot - about 100 billion Kelvin (1011 K). At this temperature, protons, electrons and neutrons had formed, but they moved with too much energy to form atoms...
  47. H

    Calculating Pressure & Mass for Hydrogen Tank Filling

    As I stated in the summary I'd like to calculate the required pressure and mass of a tank of hydrogen that would allow me to fill a second tank with 10kg of H2 at 700bar. I am trying to get an idea of the feasibility of doing this, putting aside, for now, how the primary tank would itself be...
  48. J

    Hydrogen in the Aviation Industry -- Survey

    Hello Everyone- I'm completing my Master's Degree in Commercial Aviation. I'm conducting a capstone research project about the potential of an industry shift to hydrogen, and have created a quick survey. If you have additional insight in addition to the survey, please respond in the comments...
  49. agnimusayoti

    Verify the average value of (1/r) for a 1s electron in the Hydrogen atom

    For spherical coordinate, ##dV = r^{2} \sin {\theta} dr d\theta d\phi## Therefore, $$<\frac{1}{r}> = \frac{1}{(\pi)(a_0)^{3}} \int_{0}^{\infty} {r e^{\frac{-2r}{a_0}} dr \int_0^{\pi} \sin {\theta}} d\theta \int_0^{2\pi} d\phi$$ From partial integral, I've found: $$\int_{0}^{\infty} r...
  50. L

    B Nuclear fusion question -- Calculations for Hydrogen fusing into Helium

    I read in 2 books that 4 atoms of Hydrogen fuse and give 1 atom of Helium and 2 electrons, and these 2 electrons convert to light. And that the mass of the Helium is less than the mass of the 4 atoms of Hydrogen, thus that the mass lost converted to light too. But I sum up the masses of...