Angular momentum of an electron in the second shell of a $Li^{+2}$ ion is:

When $Z$ is doubled in an atom,which of the following statements are consistent with Bohr's theory?

If the longest wavelength of the spectral line of the Paschen series of $Li^{2+}$ ion spectrum is $x \ \mathring{A}$,then the longest wavelength (in $\mathring{A}$) of the Lyman series of the hydrogen spectrum is

If the electron of a hydrogen atom is in the third orbit,it represents its ...... excited state.

Which electron level would allow the hydrogen atom to absorb a photon but not emit a photon?

The value of Planck's constant is $6.63 \times 10^{-34} \, J \cdot s$ and the speed of light is $3.0 \times 10^8 \, m \cdot s^{-1}$. The wavelength of a quantum of light with a frequency of $8 \times 10^{15} \, s^{-1}$ is closest to which of the following values in meters?