Beryllium

Element 3 - Element 4 - Element 5

Beryllium
A sample of metallic beryllium.
Atomic Number	4
Symbol	Be
Block	S
Category	Alkaline Earth Metal
Valence Electrons	2
State	Solid
Appearance	white-gray metal
Melting point	1560 K (1287 °C, 2349 °F)
Boiling point	2742 K (2469 °C, 4476 °F)
Density	1.845 g/cm³(at 20°C)
Atomic Diameter	112 pm
Discovered	1798 by Louis Nicolas Vauquelin
Stable Isotopes	Yes

Beryllium is an extremely hard metal in the alkali metal group. It is fairly stable as of the alkaline earth metals since it has a good grip on its electrons. The hardness on the Mohs scale is 5.5, and the metal is brittle and unyielding. This can help, though, as in outer space, there is no oxygen(earth) and there is no atmospheric pressure. So the metal will not break but can serve as a frame for spacecraft.

Beryllium was first discovered in beryl, a mineral also related to emeralds. Louis Nicolas Vauquelin was investigating the difference between beryl and emerald when he discovered Beryllium.

Chemical Properties

Beryllium is a fairly reactive metal. It usually exists in +2 oxidation state in its compounds. It can dissolve in non-oxidizing acids like hydrochloric acid.
${\ce {Be + 2HCl = BeCl2 + H2 ^}}$

However, it doesn't dissolve in nitric acid since a layer of oxide formed on the surface of beryllium prevents the inside of the beryllium from reacting with the acid. Solutions of beryllium salts in water are usually acidic due to the hydrolysis of beryllium ions.
${\ce {Be^2+ + 2H2O <=> Be(OH)2 + 2H^+}}$

History

Some minerals containing Beryllium, like beryl, had been used long before the element itself was discovered. When the element was discovered, it was given the name "glucinum", since some of its compounds have a sweet taste. The name "beryllium" was first used in 1828 by Friedrich Wöhler. Both names were used until 1949, when the IUPAC decided that the element should be called beryllium. The element was first isolated individually by Friedrich Wöhler and Antoine Bussy in 1828. They did the isolation by reacting molten metallic potassium with beryllium chloride(BeCl₂):
${\ce {2K + BeCl2 = Be + 2KCl}}$

Appearance in Nature

Beryl is an important source of natural Berylium metal for industry and commercial reasons. This mineral places up to 8 on the Mohs scale, and as in emeralds, there are hints of chromium.

Applications

Beryllium is used in radiation windows for X-ray tubes due to its low atomic number and low absorption of X-rays. It is sometimes added to other metals, like aluminium or copper, to form an alloy which is stronger that the metal itself.

Toxicity

Inhalation of dust of beryllium over a long time may cause disability, and can even kill people.

References

This page uses content from Wikipedia. The original article was at Beryllium. The list of authors can be seen in the page history. As with Chemistry Wiki, the text of Wikipedia is available under the GNU Free Documentation License.