Electrostatic Force :

One of the mysteries of the atom is in which the electron and the nucleus attract each other.  This attraction is known as electrostatic force, the force which contains the electron in orbit.   This force might be describes along with lines as display in above Figure .

Figure: Electrostatic Force

Without this electrostatic force, the electron that is traveling at high speed could not stay in its orbit.   Bodies which attract each other in this way are known as charged bodies.  As described previously, the electron has a negative charge and the nucleus (due to the proton) has a positive charge.