Beryllium (Be)

Steel gray metal

Beryllium is a hard, lightweight metal used in aerospace and X-ray windows, and an alkaline earth metal with a filled 2s² shell, beryllium has an exceptionally high melting point (1560 K) and stiffness-to-weight ratio. It is transparent to X-rays and used in satellite components.

Key metrics

Density1.85g/cm³

Melting point1,560K

Boiling point2,742K

Electronegativity1.57Pauling

Discovery

1798discovered

Discovered by: Louis Nicolas Vauquelin
Reactivity profile: Reactive under specific conditions
Reactivity: Medium
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[He]}\; \textcolor{#ef4444}{2_{s}^{2}}

[He] 2s2

Wave function

\Psi_{\text{Be}} \approx \frac{1}{\sqrt{4!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_4(\mathbf{r}_4) \right|

Probability density $|\Psi|^2$ across the Be valence shell.

Crystal structure

Hexagonal Close-Packed

Lattice constantsa 1.00 · b 1.00 · c 1.63

Cell anglesα 90° · β 90° · γ 120°

Coordination number12

Atoms per cell2

Atomic packing factor0.74

Physical properties

Atomic radius: 112 pm
Ionization energy: 900 kJ/mol
Electron affinity: 0 kJ/mol
Crystal structure: Hexagonal close-packed (hcp)

Oxidation states

Acid/base

Basic

Strongly acidicStrongly basic

State at 25 °CSolid

1560 K2742 K298 K

Emission spectrum

3 transitions

380450500550600650700780

VioletBlueGreenYellowRed

313.0nmBe IIUV30%

457.3nmBe IBlue50%

553.6nmBe IGreen100%

Dominant line 553.6 nmRange 313–554 nmTransitions 3