4 Be Beryllium 9.0122
Alkaline-earth metal
Beryllium 铍
[He] 2s²
- Period 2
- Group 2
- Block s
- Solid
Electron configuration
1s² 2s²
Orbital diagram (valence)
2s ↑↓
- Electrons per shell
- 2, 2
- Unpaired electrons
- 0
- Zeff (Slater)
- 1.95
Properties
- Atomic weight
- 9.0122
- Electronegativity (Pauling)
- 1.57
- First ionization energy
- 899.5 kJ/mol
- Electron affinity
- no data
- Covalent radius
- 96 pm
- van der Waals radius
- 153 pm
- Melting point
- 1560 K
- Boiling point
- 2744 K
- Density
- 1.85 g/cm³
- Melting / boiling point
- 1286.8 °C / 2470.8 °C
- Common oxidation states
- +2
- Discovered
- 1798
Natural isotopes
| Mass number A | Abundance |
|---|---|
| 9Be | 100.00 % |
Isotope masses: AME2020; abundances: IUPAC/CIAAW representative values.
Successive ionization energies
The big jumps appear where core electrons start to be removed. Ionization energies from the NIST Atomic Spectra Database.
Beryllium in the course
The lessons that discuss this element most (ranked by mentions).
Periodic trend
Group 2
Data: PubChem periodic table (public domain); atomic weights are IUPAC abridged standard values; covalent radii from Cordero et al. (2008).