(a)[2]
State two further observations linked with photoelectric emission that support a particulate nature of electromagnetic radiation.
(b)
For several wavelengths $\lambda$ of the electromagnetic radiation striking a metal surface, the maximum kinetic energy $E_{\text{MAX}}$ of the emitted electrons is measured. Figure 11.1 shows how $E_{\text{MAX}}$ changes with $\frac{1}{\lambda}$.
(b(i))[2]
Use Fig. 11.1 to find the threshold frequency $f_0$.
(b(ii))[4]
Use the line gradient on Fig. 11.1 to find a value for the Planck constant $h$. Show your working.
(c)[2]
The electromagnetic radiation now falls on a metal whose work function energy is larger than that of the metal in (b). On Fig. 11.1, sketch the variation of $E_{\text{MAX}}$ with $\frac{1}{\lambda}$.