4. Quantum Numbers
According to Heisenberg’s Uncertainty
Principle, it is not possible to give the
exact position of an electron and its
energy at the same time.
But the probability of finding an electron
in an orbital of given energy can be
determined.
5. The 3 Quantum Numbers
Principal Quantum Number, n
Azimuthal Quantum Number, l
Magnetic Quantum Number, ml
6. Principal Quantum Number
main energy level of an orbital.
Indicates the relative size of the orbital
an increase in n also means increase in
the energy of the electron in the orbital.
n= 1, 2, 3….
7. Azimuthal Quantum Number
also called Angular Momentum Number
defines the shape of the orbital.
values range from 0 to n-1.
l = n - 1
8. Azimuthal Quantum Number
l Sublevel Orbital Shape
0 sharp - s spherical
1 principal - p
dumbbell-
shaped
2 diffused - d cloverleaf
3 fundamental - f too complex
19. Exercise No. 1
Quantum Numbers
Give all the possible quantum numbers for
electrons in the 2nd energy level.
Give all the possible quantum numbers for
electrons in:
a. 3s orbital
b. 4d orbital
Give the quantum numbers in:
a. 4f3
b. 3p5
20. Exercise No. 2
Quantum Numbers
Which of the following sets of QN is NOT
possible? Write possible or impossible
and justify your answer.
a. n=2, l=1
c. n=1, ml=+1
d. l=4, ml=-3