Hydrogen Definition and 1000 Threads

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. P

    How is Hydrogen Peroxide Made via Electrolysis?

    Can someone tell me how you make hydrogen peroxide through electrolysis?
  2. K

    Hydrogen bond big problems in my mind

    I have two big problems in my mind about hydrogen bond for many years. I have checked many textbooks but all of them fails to explain what I don't understand. 1. To form a hydrogen bond (particular strong attraction) Why it is necessary for a hydrogen atom to attach to a highly...
  3. T

    Converting Helium back to Hydrogen?

    I am trying to find the reason why a helium atom cannot be turned back into a hydrogen atom. We know in a star that through nucleosynthesis helium is formed from hydrogen and the process continues to form heavier elements. Is there a similar, but in reverse process where lighter elements are...
  4. O

    Acceleration of electron in hydrogen atom

    Hello, I am currently reading about electromagnetic fields: In one of the examples in the textbook we calculate the electric field of a hydrogen proton. We then compute the electric force acting on the orbiting electron to be 8.2 \times 10^{-8} N So I thought I could get the...
  5. antibrane

    Hydrogen Atom in Magnetic Field

    I am attempting to find the probability, after time t, of a hydrogen atom in a magnetic field \vec{\mathbf{B}}=B_0\hat{\mathbf{z}} to go from \left|n,l,s,j,m_j\right\rangle \longrightarrow \left|n',l',s,j',m_j'\right\rangle where j=l+\frac{1}{2} and j'=l'+\frac{1}{2} or...
  6. K

    Hydrogen bonding and Oxygen electron count ? (how)

    Sorry to butt in on your form. Please can someone help me with this – I’m sure it’s simple to those who know but I have been thinking about these 2 problems for ages (and reading up on every website I can find) and still no answer. I am trying to get a basic understanding of this and seem to...
  7. Q

    Ehrenfest theorem and the hydrogen atom

    Is there any derivation of the bohr model for hydrogen using Ehrenfest theorem. References are appreciated.
  8. B

    Hydrogen atom to 90% the speed of light

    I do not understand if you accelerate a hydrogen atom to 90% the speed of light its mass is greatly increased. Are the forces that hold it together increased? If not how is it different, will it fall apart? If the forces are increased in relationship to the mass of the atom the energy...
  9. N

    What is the size difference between Hydrogen and Oxygen

    Hi I would like to know What the size difference ratio between Hydrogen and Oxygen gas atoms, in the form of the following question...' If i had two identically separate 1 liter containers, (one containing Hydrogen, and the other Oxygen), at the very same pounds psi, Which container...
  10. A

    Proving <n_f,l_f,m_l,f|p_j|n_i,l_i,m_l,i> for Hydrogen Atom - Homework Help

    Homework Statement Use [H_{0},r_{j}]=\frac{i\hbar}{\mu}p_{j} for the Hydrogen atom (where the j's denote the jth components in Cartesian coordinates) to prove that <n_{f},l_{f},m_{l,f}|p_{j}|n_{i},l_{i},m_{l,i}>=-i\mu\omega<n_{f},l_{f},m_{l,f}|r_{j}|n_{i},l_{i},m_{l,i}> Homework...
  11. K

    Normal Zeeman effect of hydrogen atoms

    Homework Statement When specially prepared Hydrogen atoms with their electrons in the 6d state are placed into a strong uniform magnetic field, the degenerate energy levels split into several levels. This is the so called normal Zeeman effect. A) Ignoring the electron spin what is the...
  12. K

    Volume affects temperature change? No. of hydrogen ions?

    Homework Statement a) 100 cm3 of 0.1 mol/dm3 of hydrochloric acid was added to 100 cm3 of 0.1 mol/dm3 of sodium hydroxide and a rise in temperature of 4 degrees was observed. If 200 cm3 of 0.1 mol/dm3 of hydrochloric acid and 200 cm3 of 0.1 mol/dm3 of sodium hydroxide were used, the rise in...
  13. D

    Why Is Calculating Mean Values for a Hydrogen Atom Challenging?

    Homework Statement So I've been racking my brain around the hydrogen mean values. \left\langle \frac{1}{r}\right\rangle=\frac{1}{a_0n^2}, that I can solve with the recurrence relation in Schaum: \left\langle r^k\right\rangle=\int_0^\infty r^{k+2}|R_{nl}(r)|^2dr by simply putting in...
  14. S

    Hydrogen orbits, magnetic field, orbit-spin interaction

    Homework Statement In different (scientific) sites I find different values for MF of H-1 ranging from 0.3 to 0.6 Tesla. Isn't there a generally acknowledged value? what about H-2 and H-3 ? The Attempt at a Solution using the general formula I get 1/ 8 tesla, that formula it not valid...
  15. G

    Understanding Hydrogen Bonding in Water and Fluorine: A Comparison

    Every water molecule is H-bonded with up to four other molecules (two through its two lone pairs, and two through its two hydrogen atoms. These 4 intermolecular hydrogen bonds are what contribute to water's high boiling point.. My textbook compares this with Fluorine, which it says can...
  16. H

    Creating a Fictional Recipe for Hydrogen Sulphide in a Video Game

    Hi, my name is Remi, I'm a game developer from Harvester Games. I have an important question regarding hydrogen sulphide. Do not worry- I am not planning to commit suicide with it, but I need it for a puzzle in my new game, The Cat Lady. At some point in the game the game's protagonist is...
  17. J

    Hydrolysis and hydrogen production: byproducts?

    So I'm running a current through distilled water with baking soda to produce hydrogen (to make stuff float :) ). I'm using carbon graphite electrodes and baking soda to avoid any dangerous gases like chlorine. Now its been almost a decade since I took chemistry classes and I'm wondering...
  18. N

    Looking for specific data about thrust, hydrogen, and celestial bodies

    first off, thanks to any that respond w useful info :) the end answer i need to find on the first topic is how many atoms of hydrogen are required to propel a mass of "x" at an acceleration of 1g in space (assuming no gravitic influence) but i would settle for how to figure out what the fuel...
  19. S

    Hydrogen Gas Detection: Simple & Inexpensive Devices

    Is there a simple method or inexpensive hand-held device available for Hydrogen gas detection?
  20. J

    Dutch words for hydrogen and oxygen

    So, I was just fooling around on Google Translate, and I decided to translate from Dutch to English for no good reason. I typed in hydrogen, and got back waterstof. Water-stuff! Or alternatively, water-dust, or water-material. So, I thought to myself "Hey, oxygen is also in water. Let's...
  21. C

    Calculating the threshold ionization intensity for hydrogen gas.

    Homework Statement Calculate the threshold ionization intensity for hydrogen gas. The attempt at a solution The way I tried to work it out was to use the field intensity of air which breaks down at, 3x10^6V/m. The ionization potential of oxygen is 13.618ev, 14.534ev for nitrogen and 13.598ev...
  22. S

    What is the ratio of hydrogen to helium in the Sun?

    Hi everyone, There is problem that asks how many hydrogen atoms are there in sun for each helium atom. I don't know which solution is correct: 1) to count all the hydrogens and heliums participating in one solar pp chain, or, 2) as X=0.71 and Y=0.26, there is (0.71/0.26)*2 H for each He...
  23. O

    Why doesn't the most common form of the hydrogen atom have a neutron?

    Most common isotopes of He has 2 neutrons, Li has 3 neutrons and so on right, until Z increases to higher numbers and we get to elements like iron, where the nucleus doesn't have equal numbers of protons and neutrons anymore. But why isn't the number of protons and neutrons equal in the most...
  24. V

    How Many Spectral Lines are Produced During Electron Transitions in Hydrogen?

    no of line in line spectrum is equal to jumps of electron from one shell to another. Am i correct. IN my book it is written that if a electron in hydrogen jumps from n1 to n2 then number of spectral lines is given by formula {(n1-n2)(n1-n2+1}/2. so consider a electron jump from 4th shell to 2nd...
  25. M

    Hydrogen atom in ground state: some puzzle

    I noticed many PF threads mention ground state of Hydrogen atom. At the same time it is two body problem considered to be solved by separation of variables. It is true, of course, that we can find basis wave functions (solutions of Shroedinger equation). But why does anybody think, that...
  26. T

    Collision rate termination reaction hydrogen oxygen explosion/combustion

    Hello, I'm making a question on the explosion of hydrogen/oxygen. All the things you need to know are the following. The formation of H-radicals in the H2-O2 mixture are responsible for ignition of the explosion. This means the H-radicals need to be formed faster than they are destructed to...
  27. E

    Catalyst and hydrogen ionizition

    How exactly does a catalyst (platinum.. with carbon.. something?) removes the electron from a hydrogen atom? (that means that quite a lot of energy was given to the hydrogen atom and the electron and proton separately (and the two particle system together) has more energy now.) Does the energy...
  28. L

    Muonic hydrogen, change in potential of the muon.

    Homework Statement Taking the proton to be a uniformly charged sphere of radius 1 fm, find an expression for the change in potential experienced by the muon as compared with that in the case of a point-like proton. Use first order perturbation theory to calculate the ground-state energy...
  29. S

    Hydrogen Gas Remediation: Chemicals Available

    Are there any commercially available chemicals that can assist in Hydrogen Gas remediation? Thanks.
  30. C

    Can Creation and Annihilation Operators Solve the Hydrogen Atom Problem?

    Just a quick question regarding the solution of the hydrogen atom: is it possible to solve the hydrogen atom problem via creation and annihilation operators as is the case with the harmonic oscillator? Any help here greatly appreciated! Crawf.
  31. ?

    EM attraction between a solenoid and interstellar hydrogen

    Okay I have a really odd question that might be difficult to answer. I have searched for an answer in several physics books and websites and don't think I have come across a specific answer for this question. Suppose I were to send a negative electromagnetic charge through a solenoid and want...
  32. G

    Hydrogen atom in a gravitational field

    hi does anybody of you know if there is an equation that describes an atom in a gravitational field of a star or something like that (general relativity or Newton)or do you know some results that could tell me something about the magnitude of this energy corrections? do you know a method...
  33. T

    Calculation of the dipole polarizability of the hydrogen atom

    A hydrogen atom placed in an electrical field results in a changed energy level and a changed eigenfunction, compared to the free atom. To examine this effect, we choose a homogenous electrical field of the force F, whose field lines run along parallel to the z-axis. The Schrödinger equation is...
  34. MTd2

    Hydrogen absorption capabilities by transional metals.

    I know about the typical case of Paladium, which is said to "absorb 900x its volume in hydrogen". But this is completely vague. I'd like to know more about the theory of absorption as well as of other materials, like Nickel, Niobium and other transitional metals. Would someone, please, give me...
  35. E

    Young star generations: where do they get their Hydrogen?

    Hi, I don't know what is the generation number of our solar system. But it is certainly not the first generation of stars. Because the heavy elements that made up the planets must have been synthesized during the supernovae of earlier generation stars. Let's assume a star massive enough to...
  36. R

    Closed orbits in hydrogen when exposed to vertical electric field

    Hi. I am trying to find the classical turning points in semi-parabolic coordinates for the hydrogen atom when an electric field is being applied to it in the y-axis. I am reading an article for those who are interested called Classical, semiclassical, and quantum dynamics in the lithium Stark...
  37. R

    Closed Orbit of Hydrogen Atoms. How to find the classical turning point

    Hi. I am trying to find the classical turning points in semi-parabolic coordinates for the hydrogen atom when an electric field is being applied to it in the y-axis. I am reading an article for those who are interested called Classical, semiclassical, and quantum dynamics in the lithium...
  38. A

    Conversion of hydrogen atom wave function that I don't understand

    Hello! I'm preparing for my quantum mechanics test. In the solutions of an old test I find this conversion, that I don't understand. \Psi = Nze^{-r/2a_0} = Nre^{-r/2a_0}cos\Theta N is the normalization constant, which is to be calculated. I would have guessed that z is the atomic...
  39. B

    Spherical Harmonic Hydrogen Wavefunction

    Homework Statement Give a physical explanation of why a spherically symmetric Ylm cannot describe the state of a system with non-zero angular momentum. Homework Equations The Attempt at a Solution I was thinking that if Ylm is spherically symmetric then the particle is equally...
  40. S

    Absorption spectra of molecular hydrogen

    I've been looking everywhere for information on the absorption spectra of molecular hydrogen. I need some pretty exact numbers. If anybody can point me in the right direction it would be greatly appreciated.
  41. S

    Exploring the Instability of Positronium: A Comparison with Hydrogen Atom

    I have a question about the stability of positronium. Positronium consists of an electron and a positron whereas hydrogen consists of an electron and a proton. The energy levels of positronium, ignoring fine structure, are -6.8eV/n2 whereas those for hydrogen are -13.6eV/n2. My question...
  42. Q

    Hydrogen atom - complete orthornormal set

    Hi, I was wondering if the bound solutions to the radial part of the hydrogen atom form a complete set for the functions in L^2(0,\infty). I know that the laguerre polynomials are complete and that they only differ from the radial solutions by factors of x^l * exp, so I thought that they would...
  43. I

    Hydrogen emission spectrum diagram

    Homework Statement Hydrogen atom with ionisation energy 13.6 eV is found to have an emission spectrum with lines at 1.89 eV, 10.20 eV and 12.09 eV. Draw a labelled diagram to show the energy levels of hydrogen atom by showing the transitions of electrons causing the emission of the lines...
  44. N

    RMS speed of Hydrogen Atoms in space

    Homework Statement In outer space the density of matter is about one atom per cm^3, mainly hydrogen atoms , and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres). Homework Equations.5mv^2 = 3/2 KT The Attempt...
  45. B

    How to build a hydrogen cell with nafion

    Has anyone built a hydrogen cell using nafion?
  46. N

    Rms speed of Hydrogen atoms in space

    Homework Statement In outer space the density of matter is about one atom per cm^3, mainly hydrogen atoms , and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres). Homework EquationsPV = NkT The Attempt at a...
  47. H

    Is a hydrogen free radical just a hydrogen atom?

    Hey, probably a stupid question but I can't seem to find an answer anywhere. Is a hydrogen free radical just a single hydrogen atom? A hydrogen atom has an unpaired electron bound right? Thanks in advance
  48. K

    Collision of a free electron and a hydrogen atom - energies

    Homework Statement An electron of know KE collides with a hydrogen atom in its ground state. With what possible KE may it rebound? KE = 11.5 eV 2. The attempt at a solution I assumed that the electron may either hit an orbiting electron and excite him (maximum layer is n = 2, change in KE...
  49. P

    Radial equation for atoms that are not hydrogen?

    So I've seen radial equations for Hydrogen out there (eg http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hydrad.html), where can I find one for more any arbitrary atom? admitedly, I realize that the equations become more and more complicated the larger the atom is. This is especially...
  50. J

    Exploring Zirconium Use in Reactors: Hydrogen & Oxidation

    Few things I'm curious about regarding zirconium use in reactors. I know at high temperatures it can release hydrogen from water by forming zirconium oxide. But: http://en.wikipedia.org/wiki/Zircaloy" this suggests that once a surface layer is formed no more oxidation can take place...
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