The electron in a hydrogen atom is in the first Bohr orbit $(n=1)$. The ratio of transition energies,$E(n=1 \rightarrow n=3)$ to $E(n=1 \rightarrow n=2)$,is

The longest wavelength doublet absorption transition is observed at $589 \, nm$ and $589.6 \, nm$. Calculate the frequency of each transition and the energy difference between the two excited states.

The electron in the hydrogen atom undergoes a transition from higher orbitals to an orbital of radius $211.6 \text{ pm}$. This transition is associated with:

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?

The value of the work function of a metal $X$ is $3.1 \ eV$. What is its threshold frequency (in $Hz$)? (Given: $h = 6.62 \times 10^{-34} \ J \cdot s$)

The energy of an electron in an excited hydrogen atom is $-3.4 \, eV$. According to Bohr's theory,the angular momentum of this electron in $J \cdot s$ is: