The relationship between pressure and volume at constant temperature is given by :

1. Avogadro
2. Charles
3. Boyle
4. Henry

The chemical reaction in which heat is evolved is known as:

1. Endothermic reaction
2. Exothermic reaction
3. Photochemical reaction
4. Electrolytic reaction

If an element has five electrons in its outermost shell, then it is likely to be:

1. Metallic
2. Non metallic
3. Metalloid
4. Inert gas

The double covalent molecule is :

1. Oxygen
2. Ammonia
3. Sodium chloride
4. Hydrogen sulphide