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

$\alpha$-rays have

The kinetic energy of photoelectrons depends on ...............

Explain emission and absorption spectra.

Work function $(W_0)$ values of six metals (in $eV$) are given below: $Li: 2.42, Mg: 3.7, Cu: 4.8, Ag: 4.3, K: 2.25, Na: 2.3$. How many of the above metals do not eject the electrons when they are made to strike with radiation of wavelength $400 \text{ nm}$? $(h = 6.62 \times 10^{-34} \text{ Js})$

The Vijayawada $FM$ radio station broadcasts at a frequency of $103.4 \ MHz$. The wavelength of the corresponding radio waves (in $m$) is