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प्रश्न
Write a note on ‘Principal Quantum number.
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उत्तर
Principal quantum number (n):
- Principal quantum number indicates the principal shell or main energy level to which the electron belongs.
- It is denoted by ‘n’ and is a positive integer with values 1, 2, 3, 4, 5, 6, ….
- A set of atomic orbitals with a given value of ‘n’ constitutes a single shell. These shells are also represented by the letters K, L, M, N, etc.
- With an increase of ‘n’, the number of allowed orbitals in that shell increases and is given by n2.
- The allowed orbitals in the first four shells are given below:
Principal quantum number (n) Shell symbol Allowed number of orbitals (n2) Size of shell 1 K 1 ↓ increases 2 L 4 3 M 9 4 N 16 - As the value of ‘n’ increases, the distance of the shell from the nucleus increases, and the size of the shell increases. Its energy also goes on increasing.
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संबंधित प्रश्न
Using s, p, d notations, describe the orbital with the following quantum numbers n = 1, l = 0.
Choose the correct option.
“No two electrons in the same atoms can have identical set of four quantum numbers”. This statement is known as -
Choose the correct option.
Principal Quantum number describes -
State and explain Pauli’s exclusion principle.
State Hund’s rule of maximum multiplicity with a suitable example.
State the order of filling atomic orbitals following Aufbau principle.
Write condensed orbital notation of electronic configuration of the following element:
Lithium (Z = 3)
Draw shapes of 2p orbitals.
If n = 3, what are the quantum number l and m?
Which mineral among the following contains vanadium in it?
Which one of the following orders is CORRECT in case of energy of the given subshells?
P: n = 4; l = 3
Q: n = 5; I = 1
R: n = 5; l = 0
S: n = 4; l = 2
How many electrons in 19K have n = 3, l = 1?
How many electrons can fit in the orbital for which n = 4 and l = 2?
The number of radial nodes for 3p orbital is ______.
Total number of orbitals associated with third shell will be ______.
The pair of ions having same electronic configuration is ______.
Which of the following statements concerning the quantum numbers are correct?
(i) Angular quantum number determines the three dimensional shape of the orbital.
(ii) The principal quantum number determines the orientation and energy of the orbital.
(iii) Magnetic quantum number determines the size of the orbital.
(iv) Spin quantum number of an electron determines the orientation of the spin of electron relative to the chosen axis.
The arrangement of orbitals on the basis of energy is based upon their (n + l) value. Lower the value of (n + l), lower is the energy. For orbitals having same values of (n + l), the orbital with lower value of n will have lower energy.
Based upon the above information, arrange the following orbitals in the increasing order of energy.
4s, 3s, 3p, 4d
The arrangement of orbitals on the basis of energy is based upon their (n + l) value. Lower the value of (n + l), lower is the energy. For orbitals having same values of (n + l), the orbital with lower value of n will have lower energy.
Based upon the above information, arrange the following orbitals in the increasing order of energy.
5f, 6d, 7s, 7p
The arrangement of orbitals on the basis of energy is based upon their (n + l) value. Lower the value of (n + l), lower is the energy. For orbitals having same values of (n + l), the orbital with lower value of n will have lower energy.
Based upon the above information, solve the questions given below:
Which of the following orbitals has the lowest energy?
4d, 4f, 5s, 5p
Match the quantum numbers with the information provided by these.
| Quantum number | Information provided |
| (i) Principal quantum number | (a) orientation of the orbital |
| (ii) Azimuthal quantum number | (b) energy and size of orbital |
| (iii) Magnetic quantum number | (c) spin of electron |
| (iv) Spin quantum number | (d) shape of the orbital |
Choose the INCORRECT statement
Which of the following is not the permissible arrangement of electrons in an atom?
What are the possible values of magnetic quantum number for p orbital?
