quantum number (1,2,3)?

Question

In Quantum Mechanics, what does it mean when someone says (1,1,1) or (1,2,3) or (1,2,1) etc. I know it has something to do with the electrons at certain levels but the numbers do not make sense to me. I'm doing a problem where the electrons get excited from a (1,2,1) state to a higher one... how do I figure out what the higher state is?? Is it (1,3,1)???

Answer 1

The first quantum number is the distance from the nucleus..Many books refer to this as the energy level or electron shell (K,L,M etc)
The second quantum number refers to the path that the electrons follow. Many books refer to this as sub orbitals (S,P,D,F). where 1 is the s suborbital, 2 is the p suborbital , ..etc.
The third quantum number is the orientation in space around the x,y, and z axis of the atom.