Answer: 3, 0, 0, +1/2.
- A 3, 0, 0, +1/2
- B 2, 1, 0, +1/2
- C 3, 1, 0, +1/2
- D 4, 0, 0, +1/2
Correct answer: A. 3, 0, 0, +1/2
Explanation: Na configuration: 1s²2s²2p⁶3s¹. Outermost electron in 3s: n=3, l=0, ml=0, ms=±1/2.
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.