(a(i))[1]
State an effect that gives evidence for the wave nature of a particle.
(a(ii))[1]
State an effect that gives evidence for the particulate nature of electromagnetic radiation.
(b(i))[1]
Fig. 7.1 shows four electron energy levels in an atom. For the emission spectrum formed by electron transitions between these energy levels, state the number of lines.
(b(ii))[2]
Calculate the minimum wavelength for this emission spectrum. The energy levels shown are $-0.87 \times 10^{-19}\ \text{J}$, $-1.36 \times 10^{-19}\ \text{J}$, $-2.42 \times 10^{-19}\ \text{J}$ and $-5.44 \times 10^{-19}\ \text{J}$.