Quantum Number has important role in the field of organic chemistry.

1. CHEMISTRY DEPARTMENT
WELCOMES

2. CHEMISTRY
SEMINAR
PRESENTED BY:-
BIBHU PRASAD PUHAN
TOPIC-QUANTUM NUMBER

3. Introduction:-
• Suppose just to search any person in this world 4 things are to be
needed i.e. Country,State or city which he belongs, Street and house
number similarly an electron can be identified by knowing the four
quantum numbers, which are required to locate the particular
electron in atom.
• Definition:-
• quantum numbers are the constant numbers,which are use to
specify the position and energy of an electron in an atom there are
four types of quantum number which located the electron in the
atomic orbitals.That are;

4. Types of quantum number:-
• 1) Principal Quantum Number (n)
• 2) Azimuthal Quantum Number (l)
• 3) Magnetic Quantum Number (m)
• 4)Spin Quantum Number (s)

5. 1) Principal Quantum Number (n):-
• It is denoted by n.It represents the main energy level to which
an electron belongs.It was discovered by Bohr.
• ✓ It also indicates the average distance of the electron From
the and also determines the energy of an electron.

6. The maximum number of electrons can be
calculated by the formula of 2n² ;If n=1,2,3,4 then
n may be theoretically assumed that any integral value from 1 to ∞.But so far 1 to 7 have been
established.
K-shell is the lowest energy level or ground state and q-shell is the higher energy level.

7. 2) Azimuthal Quantum Numbers (l) :-
• It is denoted by l.It is called secondary or subsidiary quantum
number.It defines the shape of the orbital.It was given by
Summerfield.The values of l is lies from 0 to n-1.Which refers to a
Subshell.
a) l=0 means s-dubshell:-Sharp
b)l=1 means p-subshell:-Principal
c)l=2 means d-subshell:-Diffused
d)l=3 means f-subshell:-Fundamental

8. Maximum electron accomodate in a
subshell Is 4l+2;
• l=0 maximum e−=2
• l=1 maximum e−=6
l=2 maximum e−=10
• L=3 maximum e−=14
• Shape of different Subshell:-
• A)s-Spherical
• B)p-Dumbell
• C)d-Double Dumbell
• D)f-Tripppled Dumbell
• Energy levels of Subshell:- s<p<d<f

9. 3) Magnetic Quantum Number (m):-
• It is denoted by m.It was given by Linden.A quantum number is the
account for splitting of spectral lines called Zeeman effect.
• Kindest purposed that under the influence of magnetic field each
subshell is further subdivided into orbitals.It also describes the
orientation or distribution of electron cloud.
• orr each values of l =2l+1(-l to +l through 0).

10. Shape of orbital:-

11. 4)Spin Quantum Number (s):-
• It is denoted by s.It is given by Goldsmith.It gives the spin of the
electron.It represents the direction of electron spin around its
own axis.
• An electron can spin either clockwise or anticlockwise.Hence for
clockwise spin:- +1⁄2
• Anticlockwise:- -1⁄2
• Total spin=n(-+1⁄2)
• When two electrons are present in an orbital,they have opposite
spin.Means each orbital can accommodate maximum two electron
with opposite spin.

12. Representation of spin quantum number:-