Beryllium
A stiff, lightweight metal used in aerospace alloys.
Inside the Beryllium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Beryllium atom step by step.
Electron configuration
[He] 2s2
A neutral Beryllium atom has 4 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Physical & atomic properties
- State (room temp)
- Solid
- Melting point
- 1560 K (1287 °C)
- Boiling point
- 2742 K (2469 °C)
- Density
- 1.85 g/cm³
- Electronegativity
- 1.57 Pauling
- Atomic radius
- 105 pm
- 1st ionization energy
- 899 kJ/mol
- Category
- Alkaline earth metals
Discovery & naming
- Discovered
- 1798
- Discovered by
- Louis-Nicolas Vauquelin
- Origin of name
- From the mineral beryl.
Notable uses
Aerospace alloys, X-ray windows, and precision instruments.
Where Beryllium comes from
Cosmic ray spallation
Skipped over by ordinary stellar fusion. Formed almost entirely when cosmic rays break apart heavier nuclei.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 4
- Atomic mass
- 9.0122
- Category
- Alkaline earth metals
- Group · Period
- 2 · 2
- Block
- s-block
- Shells
- 2 · 2