Helium
Helium (He) is a chemical element belonging to the category Noble gas, with atomic number 2 and atomic mass 4.0026 u. This sheet describes its fundamental properties, periodic position and physical characteristics.
Identity
- Name: Helium
- Symbol: He
- Atomic number: 2
- Atomic mass: 4.0026 u
Position in the periodic table
- Group: 18
- Period: 1
- Category: Noble gas
Physico-chemical properties
- Standard state: Gas
- Melting point: No melting point at 1 atm (remains liquid down to −273.15°C solidifies at −272.20°C under pressure)
- Boiling point: -268.93°C
- Density: 0.1785 g/L (0°C, 1 atm)
- Electron configuration: 1s²
Scientific description
Helium is a chemical element with symbol He and atomic number 2. It is a noble gas located in group 18 and period 1. It has no melting point at standard pressure and boils at −268.93°C. Its standard atomic mass is 4.0026 u.
KODO: G2