Hydrogen (H) — Element 1: Properties & Data | Aladdin Scientific
Hydrogen(H) — Element 1
Hydrogen (H) is a nonmetal with atomic number 1 and atomic mass 1.008. It has melting point 13.81 K (-259 °C), boiling point 20.28 K (-253 °C), density 0.00008988 g/cm³. It sits in group 1 and period 1 of the periodic table and was discovered in 1766.
Key facts
| Atomic mass | 1.0080 u |
|---|---|
| Electron configuration | 1s1 |
| Oxidation states | +1, -1 |
| Electronegativity (Pauling) | 2.2 |
| Atomic radius (van der Waals) | 120 pm |
| Ionization energy | 13.598 eV |
| Electron affinity | 0.754 eV |
| Melting point | 13.81 K |
| Boiling point | 20.28 K |
| Density | 0.00008988 g/cm³ |
| Standard state | Gas |
| Year discovered | 1766 |
Frequently asked questions
What is the electron configuration of hydrogen?
The ground-state electron configuration of hydrogen is 1s1.
What group and period is hydrogen in?
Hydrogen (H) is in group 1 and period 1 of the periodic table, classified as a nonmetal.
What is the melting point of hydrogen?
Hydrogen melts at 13.81 K (-259 °C).
What is the standard state of hydrogen?
Hydrogen is a gas at standard temperature and pressure.
Related elements
About this data: property values compiled from IUPAC Standard Atomic Weights (2021), the NIST Atomic Spectra Database, and PubChem. Curated by the Aladdin Scientific technical team. Last reviewed: .