Beryllium (Be)
Stable Isotopes of Beryllium
| Isotope | Z(p) | N(n) | Atomic Mass | Natural Abundance | Nuclear Spin |
| Be-9 | 4 | 5 | 9.0121822 | 100.00% | 3/2- |
Beryllium was discovered in 1797 by Louis-Nicolas Vauquelin. Its name derives from the Greek word beryllos, meaning "beryl."
The lightest alkaline-earth metallic element, beryllium is a hard, brittle, gray-white metal, with a hexagonal close-packed crystal system. It is the lightest structural metal known and can be fabricated by rolling, forging or machining. It is soluble in acids (except nitric acid) and alkalis. It is resistant to oxidation at ordinary temperatures, with high heat capacity and thermal conductivity. Its chemical reactions are similar to those of aluminum.
Beryllium is permeable to x-rays. It occurs in several minerals, mostly combined with silica and alumina, the most common minerals being beryl, chrysoberyl, phenacite and bertrandite. Beryllium oxide is a component of precious stones, such as emerald, aquamarine and topaz. It is found in trace amounts in the ore feldspar. It is used in nuclear reactors to moderate the velocity of slow neutrons.
Elemental beryllium and its compounds are very poisonous by inhalation or intravenous route. Chronic inhalation of beryllium dusts or fumes can cause berylliosis, a serious lung disease. Skin contact with soluble salts of the metal can cause dermatitis. Beryllium also is a carcinogen: there is sufficient evidence of its inducing cancer in animals and humans. It is one of the United States Environmental Protection Agency's listed priority pollutant metals in the environment.
Properties of Beryllium
| Name | Beryllium |
| Symbol | Be |
| Atomic number | 4 |
| Atomic weight | 9.01218 |
| Standard state | Solid at 298 °K |
| CAS Registry ID | 7440-41-7 |
| Group in periodic table | 2 |
| Group name | Alkaline earth metal |
| Period in periodic table | 2 |
| Block in periodic table | s-block |
| Color | Gray-white or lead gray |
| Classification | Metallic |
| Melting point | 1287 °C |
| Boiling point | 2970 °C |
| Thermal conductivity | 190 W/(m·K) |
| Electrical resistivity | 3.36 x 10-10 µΩ·cm at 20 °C |
| Electronegativity | 1.5 |
| Specific heat | 1820 J/(kg·K) |
| Heat of vaporization | 297 kJ·mol-1 |
| Heat of fusion | 7.95 kJ·mol-1 |
| Density of solid | 1.85 g/cm3 |
| Electron configuration | [He]2s2 |
| Oxidation state | 2+ |
| Atomic radius | 1.06 Å |
| Ionic radius | Be2+ : 0.30 Å |
Research
- Regolith evolution on the millennial timescale from combined U–Th–Ra isotopes and in situ cosmogenic 10Be analysis in a weathering profile (Strengbach catchment, France)
- A persistent and dynamic East Greenland Ice Sheet over the past 7.5 million years
- Mid-Brunhes magnetic excursions in marine isotope stages 9, 13, 14, and 15 (286, 495, 540, and 590 ka) at North Atlantic IODP Sites U1302/3, U1305 and U1306
- Early solar system irradiation quantified by linked vanadium and beryllium isotope variations in meteorites
- Rapid global ocean-atmosphere response to Southern Ocean freshening during the last glacial
- A persistent and dynamic East Greenland Ice Sheet over the past 7.5 million years
- Neogene cooling driven by land surface reactivity rather than increased weathering fluxes
- Meteoritic evidence of a late superflare as source of 7Be in the early Solar System