What does the symbol lambda (ƛ) represent in spectrophotometry?

In spectrophotometry, the symbol lambda (ƛ) specifically denotes the wavelength of light. Wavelength is a crucial parameter since it influences how different substances absorb light, affecting the accuracy and interpretability of the measurements taken. Each substance has unique absorption characteristics at particular wavelengths, determining how it responds to light.

Knowing the wavelength allows scientists to select the appropriate light source and filters in their instruments to maximize the sensitivity and specificity of detecting and quantifying substances in a sample. Wavelength plays a pivotal role in designing experiments and interpreting results, especially when working with complex mixtures where various components may absorb at different wavelengths.

The other options focus on aspects that do not directly pertain to the definition of lambda in the context of spectrophotometry. For instance, concentration, light source type, and absorbance values are important in the overall analysis, but they do not define what lambda (ƛ) represents.