Assertion (A): | All d orbitals are tetra-lobed structures having two nodal planes. |
Reason (R): | Out of five, only four d-orbitals are degenerate orbitals. |
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. |
The number of protons, neutrons and electrons in \( _{71}^{175}Lu\) respectively, are:
1. 104, 71 and 71
2. 71, 71 and 104
3. 175, 104 and 71
4. 71, 104 and 71
The energy of an electron in the first Bohr's orbit of an H-atom is -13.6 eV. The possible energy value (s) of the excited state(s) for electrons in Bohr's orbits of hydrogen is (are):
1. -3.4 eV
2. -4.2 eV
3. -6.8 eV
4. +6.8 eV
An ion among the following that has the same radius as a hydrogen atom, having n=1, is
1.
2.
3.
4.
The number of electrons with the azimuthal quantum number l = 1 and 2 for Cr 24 in ground state is
1. 16 and 5
2. 12 and 5
3. 16 and 4
4. 12 and 4
The wavelength of the radiation emitted when in a H atom, the electron falls from infinity to stationary state (n=1), is:
1.
2. 192 nm
3. 406 nm
4. 91 nm
The number of unpaired electrons in 1s2 2s2 2p3 is -
1. 2
2. 0
3. 3
4. 1
The concept that contradicts the Bohr Model of an atom is:
1. | Rutherford Model | 2. | Heisenberg's Uncertainty Principle |
3. | J.J. Thomson Model | 4. | Photoelectric Effect |
In a subshell, if the number of radial nodes is two times the number of angular nodes, then the minimum possible value of the principal quantum number (n) is:
[angular nodes are non-zero)
1. | 1 | 2. | 2 |
3. | 3 | 4. | 4 |
The wavelength of a certain line in the Balmer series is observed to be 4341 Ao for hydrogen atoms.
The electronic transition among the following may be:
1. 3 → 2
2. 4 → 1
3. 5 → 2
4. 5 → 3