The ratio of the minimum frequencies of the Lyman and Balmer series will be $......$.

The work functions (in $eV$) of $Mg, Cu, Ag, Na$ respectively are $3.7, 4.8, 4.3, 2.3$. From how many metals,the electrons will be ejected if their surfaces are irradiated with an electromagnetic radiation of wavelength $300 \ nm$ ?
$(h=6.6 \times 10^{-34} \ Js, 1 \ eV=1.6 \times 10^{-19} \ J)$

In Bohr's model of the atom,when an electron jumps from $n=1$ to $n=3$,how much energy will be absorbed?

In a hydrogen atom,the energy difference between the states $n = 2$ and $n = 3$ is $E \ eV$. The ionization energy of the $H$-atom is: (in $E$)

The radius of the first Bohr orbit of a hydrogen atom is $0.53 \times 10^{-8} \ cm$. The velocity of the electron in the first Bohr orbit is

An electronic transition in a hydrogen atom results in the formation of the $H_\alpha$ line of the hydrogen spectrum in the Lyman series. The energies associated with the electron in each of the orbits involved in the transition (in $kcal \ mol^{-1}$) are: