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Hydrogen is a chemical element; it has symbol H and atomic number 1. It is the lightest element and, at standard conditions, is a gas of diatomic molecules with the formula H 2, sometimes called dihydrogen, [11] but more commonly called hydrogen gas, molecular hydrogen or simply hydrogen.
21.45 × 10 3 kg/m 3 — Grigoriev, ... 1 H hydrogen (H 2) use: 0.08988 g/L: ... formula weight = 222 Notes
Data from same reference as for liquid hydrogen. [21] High-pressure tanks weigh much more than the hydrogen they can hold. The hydrogen may be around 5.7% of the total mass, [22] giving just 6.8 MJ per kg total mass for the LHV. See note above about use in fuel cells. Hydrogen, gas (1 atm or 101.3 kPa, 25 °C) 141.86 (HHV) 119.93 (LHV) 0.011 88 ...
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral hydrogen atom contains a nucleus of a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe. [1]
The molar mass of atoms of an element is given by the relative atomic mass of the element multiplied by the molar mass constant, M u ≈ 1.000 000 × 10 −3 kg/mol ≈ 1 g/mol. For normal samples from Earth with typical isotope composition, the atomic weight can be approximated by the standard atomic weight [ 2 ] or the conventional atomic weight.
Thus, the atomic mass of a carbon-12 atom is 12 Da by definition, but the relative isotopic mass of a carbon-12 atom is simply 12. The sum of relative isotopic masses of all atoms in a molecule is the relative molecular mass. The atomic mass of an isotope and the relative isotopic mass refers to a certain specific isotope of an element.
Metallic hydrogen (recombination energy) 216 [2] Specific orbital energy of Low Earth orbit (approximate) 33.0: Beryllium + Oxygen: 23.9 [3] Lithium + Fluorine: 23.75 [citation needed] Octaazacubane potential explosive: 22.9 [4] Hydrogen + Oxygen: 13.4 [5] Gasoline + Oxygen –> Derived from Gasoline: 13.3 [citation needed] Dinitroacetylene ...
USD/kg USD/L [c] 1: H: Hydrogen: 0.00008988: 1400 (3.878 × 10 19 kg) 1.39: 0.000 125: 2012: DOE Hydrogen [8] Prices of hydrogen produced by distributed steam methane reforming, as predicted by H2A Production Model from United States Department of Energy, [9] assuming price of natural gas of US$3/MMBtu (US$10/MWh; US$0.10/m 3). Does not include ...