Week 7: Alkali Earth Metal - Beryllium

Name: Berrylium
Symbol: Be
Atomic number: 4
Atomic weight: 9.012182(3)
Group in periodic table: 2
Group name: Alkali Earth Metal
Period in periodic table: 2
Block in periodic table: s
Color: white-grey metallic

Beryllium is found naturally only combined with other elements in minerals. Notable gemstones which contain beryllium include beryl (aquamarine, emerald) and chrysoberyl. The free element is a steel-gray, strong, lightweight brittle alkaline earth metal. It is primarily used as a hardening agent in alloys, notably beryllium copper.

The name beryllium comes from the Greek which means to "to become pale," in reference to the pale semiprecious gemstone beryl. Beryllium is a constituent of about 100 out of about 4000 known minerals and precious forms of beryl are aquamarine, bixbite and emerald.

Because of its low atomic number and very low absorption for X-rays, the oldest and still one of the most important applications of beryllium is in radiation windows for X-ray tubes. Also, due to its low atomic number, beryllium is almost transparent to energetic particles. Therefore it is used to build the beam pipe around the collision region in collider particle physics experiments. Notably all four main detector experiments at the Large Hadron Collider accelerator use a beryllium beam-pipe.

Beryllium has one of the highest melting points of the light metals. Because of its stiffness, light weight, and dimensional stability over a wide temperature range, beryllium metal is used for lightweight structural components in the defense and aerospace industries in high-speed aircraft, missiles, space vehicles and communication satellites. Several liquid-fuel rockets use nozzles of pure beryllium.

Commercial use of beryllium metal presents technical challenges due to the toxicity (especially by inhalation) of beryllium-containing dusts. Beryllium produces a direct corrosive effect to tissue, and can cause a chronic life-threatening allergic disease called berylliosis in susceptible persons.

Beryllium is a relatively rare element in both the Earth and the universe. The element is not known to be necessary or useful for either plant or animal life.