1. | \(\dfrac{r_0}{9}\) | 2. | \(r_0\) |
3. | \(9r_0\) | 4. | \(3r_0\) |
What is the ratio of the speed of an electron in the first orbit of an \(\mathrm{H}\text-\)atom to the speed of light?
1. | \(\dfrac{1}{137}\) | 2. | \(137\) |
3. | \(\dfrac{1}{83}\) | 4. | \(\dfrac{1}{47}\) |
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. \(-3.4~\text{eV}\)
In the \(n^{th}\) orbit, the energy of an electron is \(E_{n}=-\frac{13.6}{n^2} ~\text{eV}\) for the hydrogen atom.
What will be the energy required to take the electron from the first orbit to the second orbit?
1. \(10.2~\text{eV}\)
2. \(12.1~\text{eV}\)
3. \(13.6~\text{eV}\)
4. \(3.4~\text{eV}\)
If an electron in a hydrogen atom jumps from the \(3\)rd orbit to the \(2\)nd orbit, it emits a photon of wavelength \(\lambda\). What will be the corresponding wavelength of the photon when it jumps from the \(4^{th}\) orbit to the \(3\)rd orbit?
1. | \(\dfrac{16}{25} \lambda\) | 2. | \(\dfrac{9}{16} \lambda\) |
3. | \(\dfrac{20}{7} \lambda\) | 4. | \(\dfrac{20}{13} \lambda\) |
1. | \(4 \lambda_1=2 \lambda_2=2 \lambda_3=\lambda_4\) |
2. | \( \lambda_1=2 \lambda_2=2 \lambda_3=\lambda_4\) |
3. | \( \lambda_1=\lambda_2=4 \lambda_3=9\lambda_4\) |
4. | \( \lambda_1=2\lambda_2=3 \lambda_3=\lambda_4\) |
1. | its potential energy increases and kinetic energy decreases. |
2. | its potential energy decreases and kinetic energy increases. |
3. | both kinetic energy and potential energy increase. |
4. | both kinetic energy and potential energy decrease. |