Assertion (A): | The angular momentum of an electron in an atom is quantized. |
Reason (R): | In an atom, only those orbits are permitted in which the angular momentum of the electron is a natural number multiple of h/2π. |
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. |
Assertion (A): | The number of radial nodes in 3 dz2 , is zero. |
Reason (R): | The number of angular nodes of atomic orbitals is equal to the value of l. |
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): | 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): | Zn(ll) salts are diamagnetic. |
Reason (R): | Zn2+ ion has one unpaired electron. |
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. | Both (A) and (R) are false. |
Assertion (A): | Bohr’s orbits are also called stationary states. |
Reason (R): | Electrons are stationary in an orbit. |
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. |
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 these
The mass and charge of one mole of electrons are, respectively:
1. 5.48 × kg, 9.65 C,
2. 5.48 × C, 1.098 x 1027
3. 5.48 × kg, 9.65 × C
4. 9.65 × C, 1.098 x 1027
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