MAKING METALS
Very rare lump of pure metal is found lying on the ground , such as a gold nugget. But most metals occur inside rocks.Rocks especially rich in a certain metal is called a metal ore. The metal is separated from its ore by various means. Iron is obtained from its ore by various means.Iron is obtained from ore by heating them until they melt, a process called smelting. Aluminium ore is known as bauxite. To separate the aluminium, it is treated with chemicals and electricity is passed through it,a process called electrolysis. | PRECIOUS METALS
Certain types of metals are precious or valuable.This may be because they are rare and difficult to obtain from their ores, so owning them has become a symbol of power and wealth Some metals are priced for their beautiful colors and luster or sheen. Some are valuable because they are easy to hammer or cast into detailed, intricate shape such as thin wires or leave. |