First proposed to exist by Dmitri Mendeleyev in 1871. Mendeleev called it "ekasilicon". Germanium was discovered by Clemens Alexander Winkler in Germany in 1886 in a mineral sample from a silver mine. Winkler named the element as germanium for the country of Germany.
Atomic number: 32
Atomic weight: 72.63
Group, period, block: 14, 4, p
Electron configuration: 3d10 4s2 4p2
Density: 5.323 g/cm-3
Melting point: 1211.40 K,938.25 °C,1720.85 °F
Boiling point: 3106 K,2833 °C,5131 °F
Oxidation states: 4, 3, 2, 1, 0, -1, -2, -3, -4
Electronegativity: 2.01 (Pauling scale)
Ionization energies: 1st: 762 kJ·mol-1
Covalent radius: 122 pm
Van der Waals radius: 211 pm
There are five naturally occurring isotopes of germanium exist, 70Ge, 72Ge, 73Ge, 74Ge, and 76Ge.