Chemical properties of metals – Metals react with air, water, acid and form many chemical substances.

(a) Reaction with air:

Metals form their oxides when react with oxygen present in air. Metals + Oxygen → Metal oxides When ribbon of magnesium (Mg) is bum, it converts into white ash. When this ash is dissolved in a test tube with water and tested with a red litmus paper, it converts and turns into blue. Hence, it is proved that this solution (oxide) is alkaline in nature. In the same way copper and aluminium make their oxides due to which utensils of metals look dirty and non lustrous.

(b) Reaction with water:
They form metal hydroxide and release hydrogen. Sodium (Na)+ Water (H₂O) → Sodium hydroxide (NaOH) + Hydrogen (H₂)
When a very small piece of (Na) sodium is dried in a filter paper and then put into a beaker filled with water. It seems that piece of (Na) moves fast as it forms sodium hydroxide and hydrogen reacting with water. As (Na) is very reactive hence it is kept dip in kerosene, if it is kept open it bums with oxygen and reacts with water.
(c) Reaction with acid:
They produce hydrogen gas while reacting with acid.

Chemical properties of non- metals:

(a) Reaction with air: Non metals form their oxides when react with air (Oxygen). These oxide are acidic in nature. Take some powder of sulphur in a metal lid of a bottle and heat it. Wind this metal lid with a metal wire as the sulphur burn took into a gas jar cover it by a lid so the gas not to be let out. Now pour some water into a gas jar and shake it well, test the solution with blue litmus paper, it turns red. It proves that the solution is acidic. Sulphur (S) + Oxygen (O₂) → Sulphur dioxide (SO₂) Sulphur
powder reacts with oxygen which is an acidic oxide of non-metal.
(b) Reation with water: Generally non-metal do not react with water or steam, hence phosphorous are kept in water.
(c) Reaction with acids: Most of the non-metals do not react with dilute acids but sulphur react with concentrated nitric acid and form sulphur – dioxide, nitrogen oxide and water.