When an $\alpha -$particle of mass $m$ moving with velocity $v$ bombards on a heavy nucleus of charge $Z_e$ , its distance of closest approach from the nucleus depends on $m$ as

For a certain hypothetical one electron atom the wavelength (in $Å$ ) for the spectral lines for transition from $n = p$ to $n = 1$ are given by $\lambda  = \frac{{1500{p^2}}}{{{p^2} - 1}}$ (where $p > 1$ ), then the ionization potential of this element must be ......$V$ (Take $hc = 12420\ eV-Å$ )

Energy levels $A, B, C$ of a certain atom correspond to increasing values of energy i.e., $E_A < E_B < E_C$. If ${\lambda _1},{\lambda _2},{\lambda _3}$ are the wavelengths of radiation corresponding to the transition $C$ to $B, B$ to $A$ and $C$ to $A$ respectively, which of the following relation is correct ?

The diagram below shows the lowest four energy levels for an electron in a hypothetical atom.The electron is excited to the $-1\,eV$ level of the atom and transitions to the lowest energy state by emitting only two photons. Which of the following energies could not belong to either of the photons ? .....$eV$

$\alpha - $ particles of energy $400\, KeV$ are bombarded on nucleus of $_{82}Pb$. In scattering of $\alpha - $ particles, its minimum distance from nucleus will be

According to the Rutherford’s atomic model, the electrons inside the atom are