Typical electron mobility at room temperature (300 K) in metals like gold, copper and silver is 30–50 cm /(V⋅s). Carrier mobility in semiconductors is doping dependent. In silicon (Si) the electron mobility is of the order of 1,000, in germanium around 4,000, and in gallium arsenide up to 10,000 cm /(V⋅s). Hole mobilities are generally lower and range from around 100 cm /(V⋅s) in gallium arsenide, to 450 in silicon, and 2,000 in germanium.