What is the numerical value of angular momentum for an electron in first orbit of hydrogen atom? ( $\mathrm{h}=6.626 \times 10^{-34} \mathrm{Js}$ )

Which from following is NOT hydrogen like species?

Which from following statements is NOT true about isotopes?

Calculate the energy per mole of photon of electromagnetic radiation having wavelength $700 \mathrm{~nm}\left[\mathrm{~h}=6.626 \times 10^{-34} \mathrm{Js}, \mathrm{c}=3 \times 10^8 \mathrm{~m} / \mathrm{s}\right]$