The frequency of radiation with a wavelength of $5800 \ \mathring{A}$ is ... $s^{-1}$.

The $Cs^+$ ion imparts a violet color to the flame. How is this related to the emitted radiation?

Which color in the visible spectrum has the minimum energy? State its energy,wavelength,and frequency.

What is interference in the context of electromagnetic radiation?

The energy of one mole of photons of radiation whose frequency is $5 \times 10^{10} \, s^{-1}$ is .......... $J$.

Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength $8000 \ \mathring{A}$. What should be the maximum velocity of emitted electron when the same metal surface is exposed to radiation of wavelength $5000 \ \mathring{A}$? $\left( h = 6.6 \times 10^{-34} \ J \cdot s, \ m_e = 9.1 \times 10^{-31} \ kg, \ c = 3 \times 10^8 \ m/s \right)$