Hydrogen (H)
"Captain Universe, the simplest, lightest, and most common hero, fueling the very stars."
A memorable persona to anchor H in your mind.
0.089
Grams per cm³
-259.16
Celsius (°C)
120
Radius (pm)
Daily Life Link
The water you drink and the airships of classic science fiction
Discovery & History
Year Discovered
1766
Discovered By
Henry Cavendish
Origin of Name
"The name is derived from the Greek 'hydro' and 'genes' meaning water forming."
Technical Properties
Atomic Mass
1.008 u
Standard State
gas
Boiling Point
-252.879°C
Electron Configuration
1s1
1st Ionization Energy
13.598 eV
Electron Affinity
N/A
Oxidation States
"A colorless, odorless, tasteless gas."
Did You Know?
It is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass.
It's the only element that can exist without neutrons; its most common isotope (protium) is just one proton and one electron.
Hydrogen gas is so light that Earth's gravity is not strong enough to hold it, and it floats off into space.
The Sun and other stars are composed primarily of hydrogen, which they convert to helium through nuclear fusion to produce energy.