The Rutherford $\mathrm{\alpha }$-particle experiment shows that most of the $\mathrm{\alpha }$-particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom?

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 closest approach is $r_0$. What is the energy of the projectile?

If an alpha nucleus of energy $\frac{1}{2}m{v}^2$ bombards a heavy nuclear target of charge Ze, then the distance of closest approach for the alpha nucleus will be proportional to:

In an $\alpha$-particle scattering experiment, the number of particles scattered per minute in a direction perpendicular to the direction of incident particles is 40. What will be the number of particles scattered at an angle of 60° per minute?

A beam of fast-moving alpha particles were 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:

In Bohr's model if the atomic radius of the first orbit is r₀, then what will be the radius of the third orbit?
1. $\frac{{\mathrm{r}}_0}{9}$              

2. ${\mathrm{r}}_0$
3. $9{\mathrm{r}}_0$               

4. $3{\mathrm{r}}_0$

What is the ratio of the speed of an electron in the first orbit of an H-atom to the speed of light?

1.  $\frac{1}{137}$

2.  137

3.  $\frac{1}{83}$

4.  $\frac{1}{47}$

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 eV

2. 3.4 eV

3. 6.8 eV

4. –3.4 eV

In the n^th orbit, the energy of an electron is \(\mathrm{E}_{\mathrm{n}}=-\frac{13.6}{\mathrm{n}^2} \mathrm{~eV}\) 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 eV

2. 12.1 eV 

3. 13.6 eV

4. 3.4 eV 

If an electron in a hydrogen atom jumps from the 3rd orbit to the 2nd 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 3rd orbit?

1. $\frac{16}{25}\lambda$               

2. $\frac{9}{16}\lambda$

3. $\frac{20}{7}\lambda$               

4. $\frac{20}{13}\lambda$