Paper 2 Wave-Particle Duality Drills

Q1 Electron de Broglie Wavelength

An electron is accelerated from rest through $150\mathrm{V}$. Use $e=1.60\times 10^{-19}\mathrm{C}$, $m_e=9.11\times 10^{-31}\mathrm{kg}$ and $h=6.63\times 10^{-34}\mathrm{J}\mathrm{s}$.

1. Calculate the electron kinetic energy in joules. [1]
2. Calculate its momentum using $p=\sqrt{2mE}$. [2]
3. Calculate its de Broglie wavelength. [2]

Q2 Evidence Map

1. State one experiment showing particle-like behaviour of light. [1]
2. State one experiment showing wave-like behaviour of electrons. [1]
3. Explain why wave-particle duality is not simply a failure to decide whether something is a wave or a particle. [3]

Q3 Photon Momentum

A photon has wavelength $5.00\times 10^{-7}\mathrm{m}$.

1. Calculate its momentum. [2]
2. Calculate its energy. [2]
3. State how both quantities change if wavelength is reduced. [1]