1. | the first line of the Lyman series. |
2. | the second line of the Balmer series. |
3. | the first line of the Paschen series. |
4. | the second line of the Paschen series. |
The total energy of an electron in the first excited state of a hydrogen atom is about \(-3.4\) eV.
Its kinetic energy in this state will be:
1. \(-6.8~\text{eV}\)
2. \(3.4~\text{eV}\)
3. \(6.8~\text{eV}\)
4. \(-3.4~\text{eV}\)
Assertion (A): | When light consisting of wavelengths corresponding to the Balmer series is incident on a gas containing \(\mathrm{He}^{+}\) ions in the first three excited states - it can be absorbed by the \(\mathrm{He}^{+}\) ions. |
Reason (R): | All the energy levels of the \(\mathrm{He}^{+}\) ions are the same as those of the \(\mathrm{H}\) atoms. |
1. | (A) is True but (R) is False. |
2. | (A) is False but (R) is True. |
3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
What was Rutherford's atom according to classical theory?
1. | electrostatically stable. |
2. | electrodynamically unstable. |
3. | semi-stable. |
4. | stable. |
Assertion (A): | The hydrogen atom consists of only one electron but its emission spectrum has many lines. |
Reason (R): | Only Lyman series is found in the absorption spectrum of hydrogen atoms whereas in the emission spectrum, all the series are found. |
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. |
Statement I: | \(n^\text{th}\) Bohr orbit in an atom is directly proportional to \(n^3.\) | The time period of revolution of an electron in its
Statement II: | \(n^\text{th}\) Bohr orbit in an atom is directly proportional to \(n.\) | The K.E of an electron in its
1. | Statement I is incorrect and Statement II is correct. |
2. | Both Statement I and Statement II are correct. |
3. | Both Statement I and Statement II are incorrect. |
4. | Statement I is correct and Statement II is incorrect. |
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. | \(2.56 \times 10^{-13} ~\text{m},-13.6 ~\text{eV}\) |
Statement I: | The stationary orbits in Bohr's theory correspond to those orbits in which an integer number of de-Broglie wavelengths of the orbiting electron fit in. |
Statement II: | \(13.6\) eV cannot be absorbed by an \(H\)-atom in the ground state. | Photons having an energy greater than
1. | Statement I is incorrect and Statement II is correct. |
2. | Both Statement I and Statement II are correct. |
3. | Both Statement I and Statement II are incorrect. |
4. | Statement I is correct and Statement II is incorrect. |