
 Quantum Numbers 
  Since the frequency f varies with the harmonic number n, we wrote the symbol for the frequency with the subscript n, denoting which harminic number the frequency corresponds to (so that we could write, for example, that the frequency of the first overtone, corresponding to n = 2, is given from Eq. 
  As a result, the quantum state corresponding to n = 2 is called firstexcited state, and its energy is correspondingly called the energy of the firstexcited state (who could have guessed...). 
  Such a diagram shows the various energy levels (or energies of the various quantum states) stacked on top of one another, with higher energy being higher up in the diagram (that is, the energy increases as you move up in the diagram). 
 physics.mtsu.edu /~phys2020/Lectures/L6L11/L8/Quantum_Numbers/quantum_numbers.html (974 words) 
