The photon having $6000 \ \mathring{A}$ wavelength has energy $E$. If the energy of photon is $2E$,find the wavelength of the photon.

The deflection of a few $\alpha$-particles when bombarded on a thin gold foil indicates that $.......$

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:

In the hydrogen spectrum,if an electron transitions from the $6^{th}$ orbit to the $3^{rd}$ orbit through multiple steps,what is the total number of spectral lines in the $U.V.$ region?

Which of the following is $NOT$ observed in Rutherford's alpha-particle scattering experiment?

Electrons with a kinetic energy of $6.023 \times 10^4 \ J/mol$ are evolved from the surface of a metal when it is exposed to radiation of wavelength $600 \ nm$. The minimum amount of energy required to remove an electron from the metal atom is