SME
Grade 11 Science
Modern physics: photons, atomic spectra and relativity
The main lesson, then each kind of problem it solves.
Modern physics: photons, atomic spectra and relativity
Main lesson
Hydrogen’s spectral lines
Use this for “An electron in hydrogen drops from n = 3 to n = 2. What are the photon’s energy and wavelength?”
The photoelectric effect
Use this for “Light of 250 nm falls on a metal with a work function of 2.3 eV. What is the most kinetic energy an electron can leave with? What is the threshold wavelength?”
Moving clocks run slow
Use this for “A spaceship passes at 0.6c. A clock on board ticks 10 s. How long does that take as we see it? How long is the 100 m ship to us?”