Hydrogen
Hydrogen (氢, symbol H) is chemical element number 1, a Reactive Nonmetal in period 1, group 1 of the periodic table, with a standard atomic weight of about 1.008. The lightest and most abundant element in the universe. Forms the bulk of stars and is essential to organic chemistry.
Properties
| Atomic number | 1 |
|---|---|
| Symbol | H |
| Atomic mass | 1.008 u |
| Category | Reactive Nonmetal |
| Period | 1 |
| Group | 1 |
| Electron configuration | 1s¹ |
| Electronegativity | 2.2 |
| Covalent radius | 31 pm |
| Density | 0.00009 g/cm³ |
| Melting point | 14.01 K |
| Boiling point | 20.28 K |
| Discovery | Henry Cavendish, 1766 |
Overview
The lightest and most abundant element in the universe. Forms the bulk of stars and is essential to organic chemistry. Element 1, Hydrogen (H), is a Reactive Nonmetal found in period 1, group 1. As a nonmetal it tends to gain electrons, or to share them with other nonmetals when bonding.
With 1 electron in its outermost shell, Hydrogen bonds accordingly; full configuration 1s¹, electronegativity 2.2. At room temperature it is normally a gas (a very low melting point); it melts near 14.01 K (-259.1 °C), boils near 20.28 K (-252.9 °C), has a density around 0.00009 g/cm³.
Common applications range across Energy / Batteries, Industrial Gas and Agriculture / Fertiliser. Compounds featured on this site include H₂SO₄, HCl and HNO₃. On the safety side, it carries a moderate hazard rating. It was first described by Henry Cavendish in 1766.
Electron shells
Electrons per shell: 1
Main uses
- Energy / Batteries
- Industrial Gas
- Agriculture / Fertiliser
Hazard
Compounds containing Hydrogen
Data sources
Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.