Discuss the four quantum numbers. Explain the interrelationship among the four quantum numbers. Also, explain the significance of a quantum number.
Discuss the four quantum numbers. Explain the interrelationship among the four quantum numbers. Also, explain the significance of a quantum number.
QUANTUM NUMBERS: To describe the position and energy of an electron in an atom, four numbers are required, which are known as quantum numbers.
Four quantum numbers are : (a) Principal quantum number (b) Azimuthal quantum number (c) Magnetic quantum number (d) Spin quantum number
Principal Quantum Number(n): Principal quantum number was given by Bohr.
- It represents the name, size, and energy of the orbit or shell to which the electron belongs.
- Higher is the value of ‘n’, greater is the distance of the shell from the nucleus. r1 < r2 < r3 < r4 < r5 < ----
- Higher is the value of ‘n’, greater is the magnitude of energy. E1 < E2 < E3 < E4 < E5 ----
- The maximum number of electrons in a shell is given by 2n2.
- The value of n is from 1 to ∞
Azimuthal Quantum Number() :
- The azimuthal quantum number is also called the angular quantum number, subsidiary quantum number, or secondary quantum number.
- For a given value of ‘n’, the value of is from 0 to (n–1).
Value of n Values of 1 (1st shell)
0 2 (2nd shell)
0,1 3 (3rd shell)
0,1,2 4 (4th shell) 0,1,2,3
- It represents the sub-shell present in the shell.
= 0 represents s subshell.
= 1 represents p subshell.
= 2 represents d subshell.
= 3 represents f subshell.
Magnetic quantum number (m). It represents the orbitals present in the sub-shell. An orbital can be defined as :
“Region in the three-dimensional space around the nucleus where the probability of finding an electron is maximum”.
(iii) For a given value of, values of ‘m’ are from – through 0 to +.
Spin Quantum Number(s): It represents the direction of spin of an electron around its own axis. A clockwise spin is represented by +1/2 or () and anticlockwise by –1/2 or ( ). Maximum two electrons with opposite spins can be placed in an orbital.
QUANTUM NUMBERS: To describe the position and energy of an electron in an atom, four numbers are required, which are known as quantum numbers.
Four quantum numbers are : (a) Principal quantum number (b) Azimuthal quantum number (c) Magnetic quantum number (d) Spin quantum number
Principal Quantum Number(n): Principal quantum number was given by Bohr.
- It represents the name, size, and energy of the orbit or shell to which the electron belongs.
- Higher is the value of ‘n’, greater is the distance of the shell from the nucleus. r1 < r2 < r3 < r4 < r5 < ----
- Higher is the value of ‘n’, greater is the magnitude of energy. E1 < E2 < E3 < E4 < E5 ----
- The maximum number of electrons in a shell is given by 2n2.
- The value of n is from 1 to ∞
Azimuthal Quantum Number() :
- The azimuthal quantum number is also called the angular quantum number, subsidiary quantum number, or secondary quantum number.
- For a given value of ‘n’, the value of is from 0 to (n–1).
| Value of n | Values of |
| 1 (1st shell) | 0 |
| 2 (2nd shell) | 0,1 |
| 3 (3rd shell) | 0,1,2 |
| 4 (4th shell) | 0,1,2,3 |
- It represents the sub-shell present in the shell.
= 0 represents s subshell.
= 1 represents p subshell.
= 2 represents d subshell.
= 3 represents f subshell.
Magnetic quantum number (m). It represents the orbitals present in the sub-shell. An orbital can be defined as :
“Region in the three-dimensional space around the nucleus where the probability of finding an electron is maximum”.
(iii) For a given value of, values of ‘m’ are from – through 0 to +.
Spin Quantum Number(s): It represents the direction of spin of an electron around its own axis. A clockwise spin is represented by +1/2 or () and anticlockwise by –1/2 or ( ). Maximum two electrons with opposite spins can be placed in an orbital.
