Definition: L'absorbance d'une solution is a measure of how much light a colored solution absorbs, ranging from 0 to 3 (dimensionless).

Vocabulary: The spectrophotomètre measures absorbance values, which are minimal for transmitted light and maximal for absorbed light.

Example: A solution showing maximum absorbance at 520 nm (green) appears magenta to the observer.

Highlight: The Beer-Lambert law states that absorbance formule A = ε × L × C, where ε is the molar absorption coefficient, L is path length, and C is concentration.

Definition: White light spectrum encompasses all visible wavelengths from violet to red (400-800 nm).

Vocabulary: A colored solution selectively absorbs certain wavelengths while transmitting others, resulting in the perceived color.

Example: A pure iodine solution appears green because it absorbs blue light, demonstrating the principle of complementary colors.

Highlight: The perceived color of a solution is complementary to the absorbed radiation, as shown in the chromatic circle.