Thursday, August 5, 2010

nickel element

NICKEL. A silvery-white metal, symbol Ni, first isolated in 1751, but
used in alloy form with copper since ancient times. Nickel has a specific
gravity of 8.902, or a density of 0.322 lb/in3 (8,913 kg/m3), and is
magnetic up to 680°F (360°C). Its electrical conductivity is 25% that
of copper, and its thermal conductivity is 48 Btu/(ft h °F) [83 W/(m
K)]. The metal is highly resistant to atmospheric corrosion and resists
most acids, although it is attacked by oxidizing acids, such as nitric.
Sulfide ores and oxide ores are its principal sources, and its principal