1
H
1.008
Hydrogen (H)
Element 1 · Period 1 · Group 1
nonmetal
gas at room temp
s-block
About Hydrogen
The lightest and most abundant element in the universe. It makes up about 75% of all normal matter by mass.
Physical Properties
Atomic Mass
1.008 u
State at 25°C
Gas
Melting Point
-259.16 °C
Boiling Point
-252.88 °C
Density
0.0000899 g/cm³
Magnetism
Diamagnetic
Atomic Properties
Electron Configuration
1s¹
Electron Shells
1
Electronegativity
2.2
Atomic Radius
53 pm
Ionization Energy
1312 kJ/mol
Oxidation States
-1, +1
Discovery & History
Discovered By
Henry Cavendish
Discovery Year
1766
Named By
Antoine Lavoisier
Name origin: Greek: hydro (water) + gennao (forming)
Frequently Asked Questions
- Is Hydrogen a metal, nonmetal, or metalloid?
- Hydrogen is classified as a nonmetal.
- What state is Hydrogen in at room temperature?
- Hydrogen is a gas at standard room temperature (25°C).
- What is the atomic mass of Hydrogen?
- Hydrogen has an atomic mass of 1.008 atomic mass units (u).
- Who discovered Hydrogen?
- Hydrogen was discovered by Henry Cavendish in 1766.
- Where is Hydrogen on the periodic table?
- Hydrogen is element number 1, located in period 1 and group 1.