Gallery
User:Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/hydrogen.php
Emission spectrum
Physical Propertiesmass · density · phase · crystal
Atomic Mass
1.0080Da
Density
0.0001g/L
Phase (STP)
Gas
Melting Point
14.0K
Boiling Point
20.3K
Molar Heat
14.3040J/(mol·K)
Crystal Structure
HEX
Lattice Constant
3.750Å
Atomic Radiiatomic · covalent · van der Waals
Atomic (Empirical)
25.00pm
Covalent
32.00pm
Van der Waals
110.00pm
Electronic Propertieselectronegativity · ionization · affinity
Electron Configuration
1s
Electron Shells
1
Electronegativity
2.20Pauling
Electron Affinity
0.8kJ/mol
1st Ionization Energy
13.6kJ/mol
Oxidation States
-1, +1
Emission Spectrumvisible range · characteristic spectral lines
Abundanceby mass
Log scale · ppm = parts per million by mass
Biological Role
Component of water and all organic molecules. Makes up ~10% of body mass.
Discovery
Discovered By
Henry Cavendish
Named By
—
Year
1766
Nuclear Data
Known Isotopes
7
Stable Isotopes
2
Stable Mass Numbers
1, 2
Natural isotopic abundance (IUPAC recommended values)
Isotopes of H7 known
Key Compoundscontaining H
H₂O
Water
The most abundant compound on Earth's surface and the universal solvent essential for all known life
NH₃
Ammonia
A pungent gas with a trigonal pyramidal shape
H₂S
Hydrogen Sulfide
A toxic gas with a characteristic rotten-egg odor detectable at parts-per-billion concentrations
H₂O₂
Hydrogen Peroxide
A powerful oxidizer with an O–O single bond that decomposes to water and oxygen
N₂H₄
Hydrazine
A simple diamine with an N–N single bond
PH₃
Phosphine
A pyramidal molecule analogous to ammonia but far more toxic
NaHCO₃
Sodium Bicarbonate
Baking soda — a mild alkali that decomposes to Na₂CO₃, H₂O, and CO₂ when heated
H₂SO₄
Sulfuric Acid
The world's most produced chemical (~260 million tonnes/year)
HNO₃
Nitric Acid
A strong mineral acid and powerful oxidizer