Hydrogen (H)
Element 1 Ā· Reactive nonmetal
Hydrogen (H) is a chemical element with atomic number 1. It is classified as a reactive nonmetal in period 1, group 1 of the periodic table (the s-block). Its standard atomic weight is 1.008 u and its ground-state electron configuration is 1sĀ¹.
Hydrogen facts
| Atomic number (Z) | 1 |
|---|---|
| Symbol | H |
| Standard atomic weight | 1.008 u |
| Category | Reactive nonmetal |
| Group | 1 |
| Period | 1 |
| Block | s-block |
| Electron configuration | 1sĀ¹ |
| Electronegativity (Pauling) | 2.2 |
| State at 20 Ā°C | Gas |
| Protons / electrons | 1 / 1 |
| Neutrons (most common isotope, approx.) | 0 |
| Molar mass | 1.008 g/mol |