What does it mean if the $\alpha -$ particle passes through the foil of gold ?
In the Rutherford experiment, $\alpha -$ particles are scattered from a nucleus as shown. Out of the four paths, which path is not possible?
What is the atomic number of gold ?
Which one did Rutherford consider to be supported by the results of experiments in which $\alpha - $ particles were scattered by gold foil?
Hydrogen $(H)$, deuterium $(D)$, singly ionized helium $(He^+)$ and doubly ionized lithium $(Li^{++})$ all have one electron around the nucleus. Consider $n = 2$ to $n = 1$ transition. The wavelengths of emitted radiations are $\lambda_1, \lambda_2 \lambda_3$ and $\lambda_4$ respectively.