Nickel is a
chemical element; it has
symbol Ni and
atomic number 28. It is a silvery-white lustrous
metal with a slight golden tinge. Nickel is a hard and
ductile transition metal. Pure nickel is chemically reactive, but large pieces are slow to react with air under
standard conditions because a
passivation layer of
nickel oxide forms on the surface that prevents further corrosion. Even so, pure
native nickel is found in Earth's crust only in tiny amounts, usually in
ultramafic rocks,
[8][9] and in the interiors of larger
nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere.
Nickel is a
chemical element; it has
symbol Ni and
atomic number 28. It is a silvery-white lustrous
metal with a slight golden tinge. Nickel is a hard and
ductile transition metal. Pure nickel is chemically reactive, but large pieces are slow to react with air under
standard conditions because a
passivation layer of
nickel oxide forms on the surface that prevents further corrosion. Even so, pure
native nickel is found in Earth's crust only in tiny amounts, usually in
ultramafic rocks,
[8][9] and in the interiors of larger
nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere.