frequency and wavenumber of a light wave whose period is . × – s. . What is the number of photons of light with a wavelength of pm that provide 1J of energy?
. A photon of wavelength × – m strikes on metal surface, the work function of the metal being . eV. Calculate (i) the energy of the photon (eV), (ii) the kinetic energy of the emission, and (iii) the velocity of the photoelectron ( eV= .
× – J). . Electromagnetic radiation of wavelength nm is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium in kJ mol – .
. A watt bulb emits monochromatic yellow light of wavelength of . µ m. Calculate the rate of emission of quanta per second.
. Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength Å. Calculate threshold frequency ( ν ) and work function (W ) of the metal. .
What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = to an energy level with n = ? . How much energy is required to ionise a H atom if the electron occupies n = orbit? Compare your answer with the ionization enthalpy of H atom (energy required to remove the electron from n = orbit).
. What is the maximum number of emission lines when the excited electron of a H atom in n = drops to the ground state? . (i) The energy associated with the first orbit in the hydrogen atom is – .
× – J atom – . What is the energy associated with the fifth orbit? (ii) Calculate the radius of Bohr’s fifth orbit for hydrogen atom. .
Calculate the wavenumber for the longest wavelength transition in the Balmer series of atomic hydrogen. . What is the energy in joules, required to shift the electron of the hydrogen atom from the first