The Rutherford \(α -\)particle experiment shows that most of the \(α -\)particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom?
1. | The atom is hollow. |
2. | The whole mass of the atom is concentrated in a small center called the nucleus. |
3. | The nucleus is positively charged. |
4. | All of the above |
In a Rutherford scattering experiment when a projectile of charge \(Z_1\) and mass \(M_1\) approaches a target nucleus of charge \(Z_2\)
and mass \(M_2\) the distance of the closest approach is \(r_0.\) What is the energy of the projectile?
1. | Directly proportional to \(M_1 \times M_2\) |
2. | Directly proportional to \(Z_1Z_2\) |
3. | Inversely proportional to \(Z_1\) |
4. | Directly proportional to the mass \(M_1\) |
1. | \(\frac{1}{Ze} \) | 2. | \(v^2 \) |
3. | \(\frac{1}{m} \) | 4. | \(\frac{1}{v^4}\) |
1. | \(145\) | 2. | \(160\) |
3. | \(172\) | 4. | \(157\) |
A beam of fast-moving alpha particles was directed towards a thin film of gold. The parts \(A', B',\) and \(C'\) of the transmitted and reflected beams corresponding to the incident parts \(A,B\) and \(C\) of the beam, are shown in the adjoining diagram. The number of alpha particles in:
1. | \(B'\) will be minimum and in \(C'\) maximum |
2. | \(A'\) will be the maximum and in \(B'\) minimum |
3. | \(A'\) will be minimum and in \(B'\) maximum |
4. | \(C'\) will be minimum and in \(B'\) maximum |
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 \(-3.4~\text{eV}.\) 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. | \(\dfrac{20}{13} \lambda\) |