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: The radius of the second orbit of He+ is equal to that of the first orbit of hydrogen.
Reason: The radius of an orbit in hydrogen-like species is directly proportional to n and inversely proportional to Z.
1. Both the assertion and the reason are true and the reason is the correct explanation of the assertion.
2. Both the assertion and the reason are true but the reason is not the correct explanation of the assertion.
3. The assertion is true but the reason is false.
4. Both assertion and reason are false statements.
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