present if it produces J of energy. . In astronomical observations, signals observed from the distant stars are generally weak. If the photon detector receives a total of .
× – J from the radiations of nm, calculate the number of photons received by the detector. . Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nano second range. If the radiation source has the duration of ns and the number of photons emitted during the pulse source is .
× , calculate the energy of the source. . The longest wavelength doublet absorption transition is observed at and . nm.
Calcualte the frequency of each transition and energy difference between two excited states. . The work function for caesium atom is . eV.
Calculate (a) the threshold wavelength and (b) the threshold frequency of the radiation. If the caesium element is irradiated with a wavelength nm, calculate the kinetic energy and the velocity of the ejected photoelectron. . Following results are observed when sodium metal is irradiated with different wavelengths.
Calculate (a) threshold wavelength and, (b) Planck’s constant. λ (nm) v × – (cm s – ) . . .
. The ejection of the photoelectron from the silver metal in the photoelectric effect experiment can be stopped by applying the voltage of . V when the radiation . nm is used.
Calculate the work function for silver metal. . If the photon of the wavelength pm strikes an atom and one of tis inner bound electrons is ejected out with a velocity of . × m s – , calculate the energy with which it is bound to the nucleus.
. Emission transitions in the Paschen series end at orbit n = and start from orbit n and can be represeted as v = . × (Hz) [ / – /n ] Calculate the value of n if the transition is observed at nm. Find