What is the intensity of radiation?

Chlorophyll present in green leaves of plants absorbs light at $4.620 \times 10^{14} \ Hz$. Calculate the wavelength of radiation in nanometer. Which part of the electromagnetic spectrum does it belong to?

What is the wavenumber of a radiation having a wavelength of $0.25 \mu m$?

The splitting of spectral lines under the influence of a magnetic field is known as .....

The hydrogen spectrum from an incandescent source of hydrogen is:

Lines of the $Lyman$ series of the spectrum of hydrogen are in