Which statement correctly describes reflectance photometry?

• A. High color corresponds to increased reflection.
• B. High color corresponds to decreased reflection and high concentration.
• C. Low color correlates with high concentration.
• D. Reflection is independent of color.

Answer: (B)

Reflectance photometry measures the light that bounces off a sample after illumination. The color intensity of the sample determines how much light is absorbed: deeper color means more absorption, so less light is reflected back to the detector. Consequently, as color (and thus the amount of colored product) increases, the reflected light decreases. This inverse relationship is what the statement is saying: high color corresponds to decreased reflection and high concentration. The other ideas conflict with how color absorbs light—more color does not mean more reflection, low color does not imply high concentration, and reflection does depend on color.