D/B the chemical properties of metals …

Chemical properties of metals:
1. Reaction of metal with oxygen: Metals react with oxygen to form metal oxides. Metals donate electrons to oxygen for the formation of metal oxides. For example:

4K  +  O₂     <nobr>→</nobr>      2 K₂O

Metal oxides are generally basic in nature but it can also be amphoteric in nature. Amphoteric oxides mean that they are acidic as well as basic in nature. Some of the metals like sodium and potassium react vigorously with oxygen. Whenever sodium or potassium is exposed to air it catches fire. Hence, they are kept in kerosene.

2.Reaction of metal with water: Some of the metals react with water to form metal hydroxide whereas some of them do not react. Reactivity with water differs from metal to metal.

Chemical properties of non metals:

1. Reaction of non metal with oxygen: Non-metals reacts with oxygen to produce non-metallic oxides that are acidic in nature because when dissolved in water non-metallic oxides gives off non-metallic acids. Sulphur reacts with oxygen producing sulphur dioxide which on further reaction with water gives sulphurous acid.

S + O₂   → SO₂

2.Reaction of non metal with water: Non-metals do not react with water but are very reactive in air due to which they are stored in water. Phosphorous is a vigorously reacting non-metal that catches fire if exposed to air. To avoid such reaction phosphorous is stored in water that cuts off its contact with atmospheric oxygen.