When the wire is stretched with more force, the distance between its atoms increases. When this distance becomes so much that the force of attraction between the atoms remains negligible. In this situation, when the force is removed, the atoms of the material are not able to return to theis original position and the wire is not able to assume its previous shape. This is the limit of elasticity. By applying more force, the permanent position of the atoms gets disturbed and if the force is increased, further on the wire, it breaks.