Photoelectric Effect

Step 1: Understanding the Concept:
The photoelectric effect occurs only if the incident light frequency is greater than the threshold frequency (or wavelength less than the threshold wavelength).

Step 2: Detailed Explanation:
Threshold wavelength, λ₀, is in the green region (wavelength approximately 550 nm). For photoemission to occur, the incident wavelength must be less than λ₀ (or frequency higher than threshold). Order of visible light by increasing wavelength (ROYGBIV): Violet < Indigo < Blue < Green < Yellow < Orange < Red. Green is the threshold. Colors with wavelength shorter than green (Violet, Indigo, Blue) will cause photoemission. Colors with wavelength longer than green (Yellow, Orange, Red) will not. Among the options, Orange has a longer wavelength than green, so it will not emit photoelectrons.

Step 3: Final Answer:
Orange light will not emit photoelectrons.