Template:Infobox hydrogen

Hydrogen, ₀₀H
	File:H,1 Purple glow in its plasma state
Hydrogen
Appearance	colorless
Standard atomic weight Ar°(H)
	[1.00784, 1.00811]; 1.0080±0.0002 (abridged);
Hydrogen in the periodic table
	(none) ← hydrogen → helium
Group	group 1: hydrogen and alkali metals
Period	period 1
Block	s-block
Electron configuration	1s1
Electrons per shell	1
Physical properties
Phase at STP	gas
Melting point	14.01 K (−259.14 °C, −434.45 °F)
Boiling point	20.28 K (−252.87 °C, −423.17 °F)
Density (at STP)	0.08988 g/L
Triple point	13.8033 K, 7.042 kPa
Critical point	32.97 K, 1.293 MPa
Heat of fusion	(H2) 0.117 kJ/mol
Heat of vaporization	(H2) 0.904 kJ/mol
Molar heat capacity	(H2); 28.836 J/(mol·K)
Atomic properties
Oxidation states	common: −1, +1,;
Electronegativity	Pauling scale: 2.20
Ionization energies	(more);
Atomic radius	empirical: 25 pm ; calculated: 53 pm
Covalent radius	37 pm
Van der Waals radius	120 pm
	Spectral lines of hydrogen
Other properties
Natural occurrence	primordial
Crystal structure	hexagonal
Thermal conductivity	180.5 m W/(m⋅K)
Speed of sound	(gas, 27 °C) 1310 m/s
CAS Number	1333-74-0
Isotopes of hydrogen v; e;
	Category: Hydrogen; view; talk; edit; \| references

^ "Standard Atomic Weights: Hydrogen". CIAAW. 2009.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.