If in nature there may not be an element for which the principal quantum number $n > 4,$ then the total possible number of elements will be

Which statement about the Rutherford model of the atom is not true?

As an electron makes a transition from an excited state to the ground state of a hydrogen – like atom/ion

What is the atomic number of gold ? 

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.