Question 3: Which has more energy; a photon of ultraviolet radiation or a photon of yellow light?
Yellow light falls in the visible part of the electromagnetic radiations spectrum. It has a wavelength of the order of 5560 * 10-10 m.
Ultraviolet radiations fall in the range of electromagnetic radiations whose wavelength is much smaller than that the visible light. It is of the order of 3840 * 10-10 m.
Now both radiations travel with the same speed equal to c. Therefore, their energies are,
Energy of the photon of the yellow light
Energy of the photon of ultraviolet light
Comparing the two equations above, we see that Eu > Ey.
Therefore, the energy associated with photon of ultraviolet radiation will be more than the energy of the yellow light photon.