The ratio of ionization energy of Bohr's hydrogen atom and Bohr's hydrogen like lithium atom is

Apply Bohr’s atomic model to a lithium atom. Assuming that its two $K$-shell electrons are too close to nucleus such that nucleus and $K$-shell electron act as a nucleus of effective positive charge equivalent to electron. The ionization energy of its outermost electron is......$eV$

The graph which depicts the results of Rutherform gold foil experiment with $\alpha$ -particales is

$\theta:$ Scattering angle

$\mathrm{Y}:$ Number of scattered $\alpha$ -particles detected

(Plots are schematic and not to scale)

In the following diagram, which particle has highest $e/m$ value?

The radius of a nucleus is given by $r_0 A^{1 / 3}$, where $r_0=1.3 \times 10^{-15} \,m$ and $A$ is the mass number of the nucleus. The lead nucleus has $A=206$. The electrostatic force between two protons in this nucleus is approximately ................ $N$