What you’ll learn5 learning objectivesChoose one objective for a focused lesson, or study the complete topic.22.2.1Photoelectrons may be emitted from a metal surface when it is illuminated by• understand that photoelectrons may be emitted from a metal surface when it is illuminated by electromagnetic radiationSyllabus objective22.2.2The terms threshold frequency and threshold wavelength• understand and use the terms threshold frequency and threshold wavelengthSyllabus objective22.2.3Photoelectric emission in terms of photon energy and work function energy• explain photoelectric emission in terms of photon energy and work function energySyllabus objective22.2.4Hf = Φ + 1/2 mvmax 2• recall and use hf = Φ + 1/2 mvmax 2Syllabus objective22.2.5Why the maximum kinetic energy of photoelectrons is independent of• explain why the maximum kinetic energy of photoelectrons is independent of intensity, whereas the photoelectric current is proportional to intensitySyllabus objective