Made by steam methane reforming (CH4 + H2O → CO + 3 H2 over a Ni catalyst at ~800 °C) or by water electrolysis, then dried and compressed.
Research Elements H · atomic number 1 Reactive nonmetal · period 1, group 1 1s1 Shells: 1 Valence electrons: 1 in the outer shell (1s1) Green dots are the outer shell's s and p electrons. Softer green dots are the d electrons of transition metals, and the d and f electrons of lanthanides and actinides: they often take part in bonding, but not always. Grey dots are the core. Ground-state configuration from the NIST Atomic Spectra Database (A. Kramida, Yu. Ralchenko, J. Reader and the NIST ASD Team). Abundance is the mole fraction of the element found as that isotope on Earth; digits in parentheses are the uncertainty in the last digits. Masses and abundances from NIST, Atomic Weights and Isotopic Compositions (J. S. Coursey, D. J. Schwab, J. J. Tsai and R. A. Dragoset, National Institute of Standards and Technology).Hydrogen
Electrons
How it's obtained
Natural isotopes
Isotope Relative atomic mass Abundance How this isotope is separated 1H 1.00782503223(9) 0.999885(70) The bulk of natural hydrogen and the tails when D is removed; no separation is done for ordinary industrial H2. 2H 2.01410177812(12) 0.000115(70) Girdler sulfide: HDO and H2O exchange with HDS and H2S between hot (~130 °C) and cold (~30 °C) towers, and D collects in the water phase in the cold tower. Also by cascade electrolysis (D2O electrolyzes more slowly than H2O) and by cryogenic distillation of liquid H2. Molecules