Neon gas is generally used in the sign boards. If it emits strongly at '616 nm', calculate (a) the frequency of emission,

The longest wavelength doublet absorption transition is observed at 589 and '589.6 nm'. Calculate the frequency of each transition and energy difference between two excited states.

To emit a free electron from a metal surface a minimum amount of energy must be supplied.When light of frequency 7.21 * 10^14 Hz is incident on a metal surface, the maximum speed of the ejected electrons is 6 x 10^5 m/s . Calculate the threshold frequency for the metal.

Calculate the frequency of visible light of wavelength 650 nm.

Life 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 2 ns and the number of photons emitted during the pulse source is '2.5 xx 10^(15)', calculate the energy of the source.