Answer: n=3 to n=2.
- A n=2 to n=1
- B n=3 to n=2
- C n=4 to n=2
- D n=3 to n=1
Correct answer: B. n=3 to n=2
Explanation: Balmer series: transitions to n=2. First line: n=3 to n=2 (lowest energy, red H-alpha line at 656 nm).
In the photoelectric setup, light striking the metal plate ejects electrons that cross the evacuated tube to the collector, producing a measurable current on the ammeter.
Concept context
Photoelectric effect, de Broglie waves, Bohr's model, atomic spectra.