The ionisation potential of the hydrogen atom is \(13.6\) eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy of \(12.1\) eV. According to Bohr’s theory, the spectral lines emitted by hydrogen atoms will be:
1. two
2. three
3. four
4. one
The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion.
What is the atomic number \(Z\) of hydrogen like ion?
1. \(4\)
2. \(1\)
3. \(2\)
4. \(3\)
What happens when an electron makes a transition from an excited state to the ground state of a hydrogen-like atom or ion?
1. | Its kinetic energy increases but potential energy and total energy decrease. |
2. | Kinetic energy, potential energy and total energy decrease. |
3. | Kinetic energy decreases, potential energy increases but the total energy remains the same. |
4. | Kinetic energy and total energy decrease but potential energy increases. |
1. | \(0.53 \times 10^{-13} ~\text{m},-3.6 ~\text{eV}\) |
2. | \(25.6 \times 10^{-13} ~\text{m},-2.8 ~\text{eV}\) |
3. | \(2.56 \times 10^{-13} ~\text{m},-2.8 ~\text{keV}\) |
4. | \(2.56 \times 10^{-13} ~\text{m},-13.6 ~\text{eV}\) |
The de-Broglie wavelength of an electron in the second orbit of a hydrogen atom is equal to:
1. | The perimeter of the orbit. |
2. | The half of the perimeter of the orbit. |
3. | The half of the diameter of the orbit. |
4. | The diameter of the orbit. |
What was Rutherford's atom according to classical theory?
1. | electrostatically stable. |
2. | electrodynamically unstable. |
3. | semi-stable. |
4. | stable. |
1. | \(145\) | 2. | \(160\) |
3. | \(172\) | 4. | \(157\) |
1. | 2. | ||
3. | 4. |