(a)[2]
State what a photon is.
(b)[2]
Describe the appearance of a visible line emission spectrum, as observed with a diffraction grating.
(c(i))[1]
The lowest electron energy levels in a single hydrogen atom are shown in Fig. 11.1. An electron starts at the energy level $-0.85\,\text{eV}$. State how many different wavelengths can be emitted as the electron de-excites (loses energy).
(c(ii).1)[2]
Photons produced when an electron drops from the $-0.85\,\text{eV}$ level strike the surface of a platinum sample. Platinum has a work function energy of $5.6\,\text{eV}$. Determine the maximum kinetic energy, in $\text{eV}$, of a photoelectron emitted from the platinum surface.
(c(ii).2)[3]
Determine the wavelength of the photon that produces the photoelectron in part (ii) of part 1.