This presentation describes about the 4 Quantum Numbers. This presentation will be helpful in determining the possible permitted values for Shells, Subshells, Electrons and the Shapes of Orbitals

2. • Principal Quantum Number (n)
• Angular Momentum Quantum Number (l)
• Magnetic Quantum Number (ml)
• Spin Quantum Number (ms)
Quantum Numbers
Describes the location and energy of an electron
in an atom.

3. Principal Quantum Number
(n)
• Represents the Shells of an Electron.
• Determines Energy Level of an Electron.
• Maximum Number of Electrons in a given Shell = 2n2
• n (shell number) = 1, 2, 3, 4…
Shell (n) Maximum no. of Electrons
1 2
2 8
3 18
4 32

4. Angular Momentum Quantum
Number
• Represents the Subshells of an Electron.
• Determines the Angular Momentum of an Electron.
• Number of Sub-Shells (l) = n
• l (sub-shell) = 0, 1, 2, 3……(n-1)
n l Number of Sub-Shells
1 0 1
2 0, 1 2
3 0, 1, 2 3
4 0, 1, 2, 3 4
(l)

5. Orbitals
• Maximum Number of Electrons in a given Sub-
Shell = 2 x (2l + 1)
l Orbital Number of
electrons
0 s 2
1 p 6
2 d 10
3 f 14
A region of probability where an electron can
be found.

6. Magnetic Quantum Number
• Determines the Number of Types/Orientation of Orbitals.
• Number of Orientation of Orbitals (ml) = (2l+1)
• ml = -l,……..0……,+l
l ml Number of Orbitals
0 (s) 0 1
1(p) -1, 0, 1 3
2(d) -2, -1, 0, 1, 2 5
3(f) -3, -2, -1, 0, 1, 2, 3 7
(ml)

7. Orbitals
• Number of Orbitals for a given Shell = n2
Shell (n) Number of Orbitals Set of Orbitals
1 1 1s
2 4 2s 2px, 2py, 2pz
3 9 3s 3px, 3py, 3pz 3dxy, 3dyz,
3dxz, 3dz
2
, 3dx2-y2

8. Shapes of Orbitals

9. Spin Quantum Number
• Represents the Direction of Spin of an Electron
on its own Axis.
• Electrons can Spin either Clockwise ↑ or
Anticlockwise ↓ Direction.
• ms =-1/2 or +1/2
(ms)

10. Principal
Q.N. (n)
Angular
Momentum Q.N.
(l)
Magnetic Q.N. (ml) Spin
Q.N.
(ms)
Designation
of Orbital
1 0 0 ± ½ 1s
2 0
1
0
-1, 0, +1
± ½
± ½
2s
2p
3 0
1
2
0
-1, 0, +1
-2, -1, 0, +1,+2
± ½
± ½
± ½
3s
3p
3d
4 0
1
2
3
0
-1, 0, +1
-2, -1, 0, +1,+2
-3, -2, -1, 0, +1,+2, +3
± ½
± ½
± ½
± ½
4s
4p
4d
4f
Permissible Values of Q.N.