Describe Geiger-Marsden scattering experiment.
As shown in above figure, they directed a beam of $5.5 \mathrm{MeV} \alpha$-particle emitted from a ${ }_{83}^{214} \mathrm{Bi}$ radioactive source at a thin metal foil made of gold. $\alpha$-particles emitted by a ${ }_{83}^{214} \mathrm{Bi}$ radioactive source were collimated into a narrow beam by their passage through lead bricks. As shown in the figure below, the beam was allowed to fall on a thin foil of gold of thickness $2.1 \times 10^{-7} \mathrm{~m}$.
The scattered $\alpha$-particles on striking the screen produced brief light flashes (scintillations).
These flashes may be viewed through a microscope and the distribution of the number of scattered particles may be studied as a function of angle of scattering.
Orbital acceleration of electron is
If the force between the electron in the first Bohr orbit and the nucleus (proton) in hydrogen atom is $F$, then the force between them when the electron is in the second orbit is
The following diagram indicates the energy levels of a certain atom when the system moves from $4E$ level to $E$. A photon of wavelength $\lambda _1$ is emitted. The wavelength of photon produced during it's transition from $\frac{7}{3}E$ level to $E$ is $\lambda_2$. The ratio $\frac{{{\lambda _1}}}{{{\lambda _2}}}$ will be
The wavelength of the first line of Balmer series of hydrogen atom is $\lambda \,\mathop A\limits^o $. The wavelength of this line of a double ionised lithium atom $(Z = 3)$is
In the Rutherford experiment, $\alpha -$ particles are scattered from a nucleus as shown. Out of the four paths, which path is not possible?