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Beryllium (Be)
Beryllium (symbol Be) is the chemical element with atomic number 4: an alkaline earth metal, solid at 0 °C, with an atomic mass of 9.0122 u. Discovered in 1798 (Louis-Nicolas Vauquelin).
Beryllium is a metal that is both very light and very stiff, a rare combination. It is transparent to X-rays and holds its shape in the frigid temperatures of space. Most of us know it without realizing, through the gems of the beryl family: emerald and aquamarine. Its dust, however, is highly toxic.
Key facts
- Atomic number
- 4
- Symbol
- Be
- French name
- Béryllium
- Atomic mass
- 9.0122 u
- Molar mass
- 9.0122 g/mol
- Family
- Alkaline earth metals
- Position
- period 2, group 2, s-block
- State at 0 °C
- Solid
- Melting point
- 1,286.9 °C
- Boiling point
- 2,468.9 °C
- Density
- 1.85 g/cm³
- Electronegativity (Pauling)
- 1.57
- First ionization energy
- 900 kJ/mol
- Atomic radius
- 105 pm
- Electron configuration
- [He] 2s²
- Abundance in Earth's crust
- 2.8 ppm (48th most abundant element)
- Indicative price
- 860 $/kg (order of magnitude)
- Radioactive
- no
- Discovery
- 1798, Louis-Nicolas Vauquelin
Origin of the name
From beryl, the gemstone it was extracted from.
What does beryllium look like?
A steel-gray, hard and brittle metal with a slightly matte look. It is barely denser than magnesium but about four times stiffer than aluminium.
Where is beryllium found?
Rare: about 2 to 3 ppm of Earth's crust. It is not made in stars but by cosmic rays smashing heavier atoms. It is found in pegmatites and weathered volcanic rocks.
Natural sources
- Beryl (emerald, aquamarine)
- Bertrandite
- Chrysoberyl
How is beryllium produced?
The ore is converted to hydroxide, then to fluoride, which is reduced with magnesium to obtain the metal. World production is no more than a few hundred tonnes of beryllium a year, making it a strategic and costly metal.
Top producers
- United States
- China
- Mozambique
What is beryllium used for?
- Space telescope mirrors (James Webb, Spitzer).
- Copper-beryllium alloys for springs, connectors and spark-proof tools.
- X-ray-transparent windows in radiology equipment.
- Neutron reflectors in nuclear reactors.
- Aerospace and satellite parts.
In everyday life
- Emerald or aquamarine jewelry
- Connectors in some smartphones and computers
- Spark-proof tools used in refineries
Role in living things
No known biological role. The body cannot clear it properly, and it disrupts the immune system.
Hazards of beryllium
Inhaled beryllium dust can cause berylliosis, a chronic and incurable lung disease, sometimes after a single exposure in susceptible people. It is classified as a human carcinogen. Solid metal is harmless to touch; it is machining that calls for strict precautions.
Cosmic origin
- Cosmic rays: Born from the fragmentation of heavier atoms struck by high-energy particles.
History of beryllium
In 1798, French chemist Louis-Nicolas Vauquelin discovered a new oxide in beryl and emerald. Because its salts tasted sweet, it was first named “glucinium,” a name used in France until the mid-20th century. The metal was isolated independently in 1828 by Friedrich Wöhler and Antoine Bussy.
Did you know?
- The 18 hexagonal mirrors of the James Webb Space Telescope are made of beryllium coated with a thin layer of gold.
- Emerald and aquamarine are the same mineral, beryl: only the impurities (chromium or vanadium versus iron) change the color.
- 19th-century chemists tasted their compounds, which is how the sweet, and dangerous, flavor of beryllium salts was noticed.
Isotopes of beryllium
A single stable isotope, beryllium-9. Beryllium-10, made by cosmic rays in the atmosphere, is used to date ice and exposed rock.
- beryllium-7: radioactive, half-life 53.2 days. Made by cosmic rays, it traces air masses and sediments.
- beryllium-9: 100% of natural beryllium, stable
- beryllium-10: radioactive, half-life 1.39 × 10⁶ years. A cosmogenic isotope used to date rock exposure, erosion and ice cores.
Related elements
Same family (alkaline earth metals): Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra).
Same column (group 2): Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra).