Justin Luther, age 12, of Reno, Nev., for his question:

WHERE IS NICKEL FOUND?

Nickel is a white metallic chemical element often used in alloys. Nickel is magnetic, takes a high polish and does not tarnish easily or rust. Sudbury District in Ontario. Canada, supplies about a fourth of the world's nickel. Other nickel producing areas of the world include Russia, New Caledonia, Cuba and Australia.

The chief mineral ore, of nickel is pentlandite, a mixture of sulfur, iron and nickel. Other nickel ores include millerite and niccolite.

Ores obtained in Sudbury District in Ontario contain pentlandite and iron and copper sulfides.

Nickel is used in structural work and in electroplating chiefly because of its resistance to corrosion. Publishers often have printing plates electroplated with nickel to make them able to withstand hard use.

Nickel peroxide, a nickel compound, forms the active material of the positive electrode in the Edison storage battery. Nickel is also used in the nickel cadmium storage battery.

An important use for nickel is to promote certain chemical reactions by catalysis. The nickel itself is not changed in the process and can be used repeatedly. Nickel is used as a catalyst in a process called hydrogenation. In this process, the nickel causes some organic compounds to combine with hydrogen to form new compounds. Hydrogenation produces solid vegetable oils for cooking.

Perhaps the largest use for nickel is as an additive to cast iron and steel. It improves the properties of these substances in many ways. It makes iron more ductile, or easily formed, and increases its resistance to corrosion.

Nickel also makes steel more resistant to impact.

Because nickel makes steel more resistant to impact, manufacturers frequently use steel alloyed with nickel to make armor plate and machine parts.

Invar, an alloy of nickel, iron and other metals, is valued for meter scales and pendulum rods. It expands or contracts very little as its temperature changes.

Monel metal is an alloy of copper and nickel used in sheet metal work.

Nickel silver, also called German silver, is a nickel alloy used in tableware.

Nickel's atomic number is 28 and its atomic weight is 58.71. It can be hammered into thin sheets or drawn into wires. One pound of pure nickel could be drawn into a wire 80 miles long.

Axel Cronstedt, a Swedish scientist, discovered nickel in 1751.