Liquids A and B form an ideal solution at 30°C, the total vapour pressure of a solution containing 1 mol of A and 2 mol of B is 250 mmHg. The total vapour pressure becomes 300 mmHg when 1 more mol of A is added to the first solution. The vapour pressures of pure A and B at the same temperature are
Such a group of atoms is called a molecule. Obviously, there must be some force that holds these constituent atoms together in the molecules. The attractive force which holds various constituents (atoms, ions, etc.) together in different chemical species is called a chemical bond.
There are 4 types of chemical bonds which are formed by atoms or molecules to yield compounds.