Beryllium combines low density with specialized material uses. Its alloys appear in springs and electrical contacts, and thin beryllium foil transmits X-rays unusually well for a metal. The element occurs in minerals including beryl, whose varieties include emerald and aquamarine.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
Why must an X-ray window transmit radiation while still separating two environments?
Thin elemental beryllium foil
FOLLOW THIS RELATIONSHIP
Identify the barrier's jobs
An instrument window separates the inside of an apparatus from its surroundings while allowing the intended radiation to pass toward a sample or detector.
Explore the model (optional)
BeFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Atomic identity, reference properties and structure models
INTERACTIVE 3D4 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[He] 2s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
Beryl and emerald provided the evidence that led Vauquelin to recognize a new element in 1798. The initial discovery concerned its compounds, not an isolated piece of metal. Wöhler and Bussy independently obtained the metal in 1828. Early naming reflected both the mineral source and historical observations of compounds; modern work identifies substances analytically rather than repeating unsafe historical practices.
1798
New element recognized
Vauquelin identified a previously unrecognised ingredient in beryl and emerald.
1828
Metal isolated independently
Wöhler and Bussy separately obtained beryllium metal.
Beryllium occurs in minerals including beryl and bertrandite. Emerald and aquamarine are varieties of beryl, so a gemstone can contain the same element used in an engineered metal component. The mineral's appearance and properties belong to its complete chemical structure rather than to beryllium alone.
Beryllium combines low density with high stiffness and transmits X-rays comparatively well for a metal. Its and have different properties from the pure element. These specialized advantages require controlled industrial handling because inhaled beryllium-containing dust is hazardous; the applications are not household experiments.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
solid
293.15 K, 101.325 kPa
Melting point in K
1560 K
at standard pressure unless noted
Boiling point in K
2742 K
101.325 kPa
Density in g/cm³
1.85 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
1.57 Pauling
Pauling scale
First ionization energy in kJ/mol
899.5 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
96 pm
single-bond covalent radius
Common oxidation states
+2
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
2.8 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1798 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 2
Be 1.57 Pauling · Beryllium
Electronegativity across period 2. Exact values.
Li
0.98
Be
1.57
B
2.04
C
2.55
N
3.04
O
3.44
F
3.98
Electronegativity down group 2
Be 1.57 Pauling · Beryllium
Electronegativity down group 2. Exact values.
Be
1.57
Mg
1.31
Ca
1
Sr
0.95
Ba
0.89
Ra
0.9
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
