Assertion (A): | In the third energy level, there is no f subshell. |
Reason (R): | For n = 3, the possible values of l are 0, 1, 2 and for f subshell l = 3. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Assertion (A): | The radius of the second orbit of He+ is equal to that of the first orbit of hydrogen. |
Reason (R): | The radius of an orbit in hydrogen-like species is directly proportional to n and inversely proportional to Z. |
1. | Both (A) and (R) are True and (R) is the correct explanation of the (A). |
2. | Both (A) and (R) are True and (R) is not the correct explanation of the (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
If the electronic structure of oxygen atom is written as it would violate:
1. Hund's rule.
2. Paulis exclusion principle.
3. Both Hund's and Pauli's principles.
4. None of the above.
The ratio of the wavelengths of the last lines of the Balmer to Lyman series is
1. | 4:1 | 2. | 27:5 |
3. | 3:1 | 4. | 9:4 |
The maximum number of neutrons are present in the nuclei of:
Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. The frequency (ν) and wave number of this yellow light would be, respectively:
1. 517 × 1014 s–1 , 172 × 106 m–1
2. 6.17 × 1014 s–1 , 1.72 × 106 m–1
3. 4.17 × 1014 s–1 , 2.72 × 106 m–1
4. 5.17 × 1014 s–1 , 1.72 × 106 m–1
The energy of the photon with a frequency of 3 × 1015 Hz is:
1. 1.988 × J
2. 1.588 × J
3. 1.288 × J
4. 2.988 × J
A photon of wavelength 4 × 10–7 m strikes a metal surface, the work function of the metal being 2.13 eV. The kinetic energy of emission would be:
1. | 0.97 eV | 2. | 97 eV |
3. | 4.97 × eV | 4. | 5.84 × 105 eV |
The possible values of n, l, and m for the electron present in 3d would be respectively:
1. n = 3, l = 1, m = – 2, – 1, 3, 1, 2
2. n = 3, l = 3, m = – 2, – 1, 0, 1, 2
3. n = 3, l = 2, m = – 2, – 1, 0, 1, 2
4. n = 5, l = 2, m = – 2, – 1, 0, 1, 2
A certain particle carries 2.5 × 10–16 C of static electric charge. The number of electrons present in it would be:
1. | 1460 | 2. | 1350 |
3. | 1560 | 4. | 1660 |