Hydrogen Element Properties
Complete reference for Hydrogen (H, element 1): atomic data, electron configuration, isotopes, physical constants, and chemical behavior.
Hydrogen
Reactive Nonmetal — Period 1, Group 1
Atomic Identity
Electron Configuration
1 unpaired electron
Isotopes of Hydrogen
| Isotope | Symbol | Protons | Neutrons | Mass (u) | Natural Abundance | Stability |
|---|---|---|---|---|---|---|
| Protium | ¹H | 1 | 0 | 1.00782503207 | 99.9885% | Stable |
| Deuterium | ²H (D) | 1 | 1 | 2.01410177785 | 0.0115% | Stable |
| Tritium | ³H (T) | 1 | 2 | 3.01604927767 | Trace (radioactive) |
Unstable
Radioactive — β⁻, t½ = 12.32 yr |
Physical Properties
Chemical Properties
Ground State Quantum Numbers
Balmer Series Spectral Lines
Key Facts About Hydrogen
Most Abundant Element
Hydrogen makes up roughly 75% of all baryonic matter in the universe, and over 90% of all atoms.
Lightest Element
With an atomic mass of 1.008 u, hydrogen is the lightest of all elements and the lightest gas.
Stellar Fusion Fuel
Stars like the Sun convert hydrogen to helium via nuclear fusion, releasing enormous energy via E=mc².
Clean Energy Carrier
When burned or used in fuel cells, hydrogen produces only water. It is central to green energy strategies globally.
Metallic Hydrogen
Under pressures exceeding 495 GPa, hydrogen becomes a metallic conductor — observed experimentally in 2017.
Water (H₂O)
Two hydrogen atoms bond to one oxygen to form water — the most important compound for life on Earth.
Summary
Complete reference for Hydrogen (H, element 1): atomic data, electron configuration, isotopes, physical constants, and chemical behavior.
How it works
- Browse the atomic identity section for symbol, atomic number, and standard atomic weight.
- Check the electron configuration panel for orbital notation and quantum numbers.
- Review the isotopes table for protium, deuterium, and tritium data including natural abundance.
- Consult the physical properties panel for melting point, boiling point, density, and state at STP.
- Use the chemical properties section to understand reactivity, oxidation states, and electronegativity.
- Copy any value with one click for use in reports or calculations.
Use cases
- Look up hydrogen constants for chemistry homework or exams.
- Verify atomic data when writing lab reports.
- Reference isotope masses for nuclear chemistry calculations.
- Check thermodynamic constants for engineering or energy calculations.
- Teach or learn the structure of the periodic table starting with element 1.
- Confirm electron configuration before writing molecular orbital diagrams.
- Compare hydrogen isotope properties for deuterium or tritium applications.
- Quick-reference electronegativity and ionization energy for bond analysis.