OUTCOME
By the end of this lesson you will be able to examine the results of Lenard's experiment to show that light could not be a wave but is acting in packets like a particle. You will use analysis to determine the kinetic energy, work function and energy of the photon
The results of Lenard's experiment lead to Einstein recognising that light must come in 'quanta' or packets. The kinetic energy of the photelectron is a result of the energy of the incident photon minus the work to release it from the atom.
Ek = E - W
LEARNING TASKS
Explain
1. Where does the kinetic energy of the electron come from?
2. Describe the mechanism of how the energy of a photon is used to release an electron
Explore and Elaborate
Use the Phet photoelectric effect to generate data for another metal
Plot these on the same axis as last lessons data.
Evaluate
Ex 11.3