Germanium

Symbol: Ge
Atomic number: 32
Category: metalloids
Group: 14
Period: 4
Block: p
Atomic weight: 72.64 g/mol
Electrons per shell: 2, 8, 18, 4
CAS number: 7440-56-4
Phase: solid
Density: 5.323 kg/l (near room temperature)
Melting point: 1211.40 K(938.25C, 1720.85F)
Boiling point: 3106 K (2833C, 5131F)
Crystal structure: diamond cubic
Oxidation states: 4, 3, 2, 1, 0, -1, -2, -3, -4
Electronegativity: 2.01 (Pauling scale)
Name's origin: Germania
Name's meaning: the Latin word for Germany, after the discoverer's father land
Facts:
- five naturally occurring isotopes ranging in atomic mass number from 70 to 76
- is relatively abundant in the Earth's crust
- is an important semiconductor material used in transistors and various other electronic devices
- is mined primarily from sphalerite, though it is also recovered from silver, lead, and copper ores
- is not thought to be essential to the health of plants or animals
- most notable physical characteristics of germania (GeO2) are its high index of refraction and its low optical dispersion - these make it especially useful for wide-angle camera lenses, microscopy, and for the core part of optical fibers
- has little or no impact on the environment because it usually occurs only as a trace element in ores and carbonaceous materials, and is used in very small quantities in commercial applications