We already know that atoms are the building blocks of matter. Under normal conditions no atom exists as an independent (single) entity in nature, except Noble gases. However, a group of atoms is found to exist together as one species. Such a group of atoms is called molecule. Obviously there should be a force to keep the constituent atoms together as the thread holds the owers together in a garland. is attractive force which holds the atoms together is called a bond.
A Chemical bond may be
defined as the force of attraction between the two atoms that binds them
together as a unit called molecule.