Materials : Metals and Non-Metals
Chemical elements can be classifies as metals and non-metals. Some metals as well as non-metals occur in free state.
Most of the metals are solid under normal conditions of temperature and pressure. The property of metals having a shining surface is called metallic lustre. Metals also show property of sonority. Metals show property of malleability. Metals are ductile and good conductors of heat and electricity.
Metals are reactive towards oxygen, water, dilute acids and show displacement reaction. Metals react with oxygen to give basic oxides. Metals react with water to produce metal hydroxides/ metal oxide and hydrogen gas. Metal oxides are basic in nature, so they turn red litmus blue.
When the surface of a metal is attacked by air, moisture or a chemical substance (such as an acid), the metal corrodes and the phenomenon is known as corrosion.
Metals are used in various fields such as making of machinery, vehicles, satellites etc.
Non-metals display the properties that are mostly opposite to metals. Non-metals may exist as solid, liquid or gas at room temperature. Non-metals are brittle. They do not have lustre except iodine and graphite. Non-metals are bad conductors of electricity. Non-metals react with oxygen to form acidic or neutral oxides. Non-metallic oxides are acidic in nature. Non-metals are used for various purposes.