1st - Principle QN
n
2nd - Orbital QN
l
3rd - Magnetic QN
ml
4th - Spin
QN
ms
n = 1,2,3...7
l goes from 0 to n-1 within an energy level
l values = 0 (for s) , 1(for p) , 2 (for d), 3 (for f) sublevels
Values of ml go from +l to - l , which gives 2l + 1 number of values
has 2 values: 1. measures the average distance of the
e- from the nucleus
1. indicates the shape of the orbital ( set of probable
locations of the e- )
1. identifies the direction in e- orbital has
around the nucleus
1. identifies the "spin" or rotation of the
e- about its own axis
2. different values of n mean different energy
levels
2. diff. values of l mean diff sublevels. In a
sublevel all the e- have nearly the same energy.
2. specifies the e- orbital in which the
e- is located within a sublevel.
2. shows that each orbital can contain only 2
e-
3. different values of n mean relatively large
differences in the energies of the e-s
3. different sublevels within the same level may have
moderately large differences in energy.
3. different values of ml mean little difference
in energies of the e-
3. the direction of spin is either in one direction or the other
4. the smallest avgerage distance and the lowest energy occurs
when n = 1; each increase in n increases those quantities.
4. within any level, the lowest energy sublevel is s, then p, then d, then f.
4. the number of possible values of ml within a sublevel
idenities how many e- pairs that the sublevel can hold
4. when 2 e- (in an atom) have the same set of
QN except for ms ,
then these e- are called an e- pair
5. the number of e- possible in a level is 2n2
5. the number of possible values of l for a level is equal to the
value of n
5.these e- within an e- pair have
essentially the same energy
+1/2 (spin up) and -1/2(spin down)
Go to notes on Electronic Structure of the Atom