Beryllium
Beryllium is the chemical element with the symbol Be and atomic number 4.
Contents
Properties
Chemical
Beryllium is more chemically similar to aluminium than its close neighbors in the periodic table, due to having a similar charge-to-radius ratio. A protective oxide layer forms around beryllium that prevents further reactions with air unless heated above 1000 °C. It will dissolve in alkali solutions and non-oxidizing acids, such as hydrochloric acid releasing hydrogen gas, but not in nitric acid, as it forms a protective oxide layer, similar to aluminium. It will also dissolve in alkali solutions.
Like aluminium halides, beryllium halides tend to be covalent due to the small atomic radius and high charge density.
Physical
Beryllium is a white-gray and hard metal, brittle at room temperature and has a close-packed hexagonal crystal structure. It has exceptional stiffness (Young's modulus 287 GPa) and a reasonably high melting point. Beryllium has high specific heat (1925 J·kg−1·K−1) and thermal conductivity (216 W·m−1·K−1), which make beryllium the metal with the best heat dissipation characteristics per unit weight. Beryllium has the fastest speed of sound in any known metal, with a value of 12.9 km/s at standard conditions.
Availability
Beryllium samples can be bought online from Metallium, in ampoules (recommended) or pellets and rods.
Beryllium can be found in beryllium copper/bronze tools, in concentrations between 0.5—3%.
Preparation
Beryllium metal can be prepared by reducing beryllium chloride with potassium metal, in an inert atmosphere:
- BeCl2 + 2 K → 2 KCl + Be
It can also be prepared from the electrolysis of a mixture of molten beryllium fluoride and sodium fluoride.
Projects
- Synthetic gemstones
Handling
Safety
Although beryllium and beryllium compounds have interesting properties worth studying, both are extremely toxic, and inhaling their dust can result in a serious medical condition called "berylliosis". The International Agency for Research on Cancer (IARC) lists beryllium and beryllium compounds as Category 1 carcinogens.
