Nitrogen laser produces a radiation at a wavelength of 337.1 nm. If the number of photons emitted is `5.6 xx 10^24`, Calculate the power of this laser.

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

The energy of a photon is 10 xx 10^-19J .Calculate its wavelength.

The work function of silver is 5.26 xx 10^-19J . Calculate its threshold wavelength.

The number of atoms of oxygen in 6.02 xx 10^24 CO molecules is________.

Calculate the wavelength, frequency and wave number of a light wave whoce periods is 2.0 xx 10^-10 s .

A radio transmitter operates at a frequency of 880 kHz and a power of 10 kW . The number of photons emitted per second are

Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise sodium atom. Calculate the ionisation energy of sodium in kJ mol^-1 .

Calculate the energy of a photon of frequency 6.2 xx.10^14 Hz .