Which observations are not explained by the electromagnetic theory of physics?

$A$ certain transition in the hydrogen spectrum from an excited state in one or more steps gives rise to a total of $10$ lines. The number of lines lying in the visible spectrum is:

Which one of the following transitions of an electron in a hydrogen atom emits radiation of the lowest wavelength?

In Rutherford's experiment,generally the thin foil of heavy atoms,like gold,platinum etc. have been used to be bombarded by the $\alpha$-particles. If the thin foil of light atoms like aluminium etc. is used,what difference would be observed from the above results?

When an electron transitions from the $6^{th}$ orbit to the $2^{nd}$ orbit in a $H$ atom,what is the total number of spectral lines (excluding the Balmer series) produced?

Emission transitions in the Paschen series end at orbit $n=3$ and start from orbit $n$ and can be represented as $\nu = 3.29 \times 10^{15} \, Hz \left(\frac{1}{3^2} - \frac{1}{n^2}\right)$. Calculate the value of $n$ if the transition is observed at $1285 \, nm$. Find the region of the spectrum.