what is relation between quantized energy and principle quantum number?E= – 1/n2 …....so what does it mean? by increasing shell nu energy become less negative …. so what we say will it increase or decrease???? plz give explaination

The motion of the electron is not free. The electron is bound to the atom by the attractive force of the nucleus and consequently quantum mechanics predicts that the total energy of the electron is quantized.....Since the motion of the electron occurs in three dimensions we might correctly anticipate three quantum numbers for the hydrogen atom. But the energy depends only on the quantum number n and for this reason it is called the principal quantum number. In this case, the energy is inversly dependent upon n2, and as n is increased the energy becomes less negative with the spacings between the energy levels decreasing in size. When n = ¥ , E = 0 and the electron is free of the attractive force of the nucleus. The average distance between the nucleus and the electron (the average value of r) increases as the energy or the value of n increases. Thus energy must be supplied to pull the electron away from the nucleus