Question

what does a spectrometer physically measure? *
absorbance of light at a specific wavelength
absorbance of light at all wavelengths
reflection of light at a specific wavelengths
reflection of light at all wavelengths

Explanation:

A spectrometer measures the absorption of light across different wavelengths. It separates light into its component wavelengths and can determine how much of the light is absorbed at each wavelength. It is not primarily about reflection, and not just at a single specific wavelength but across a range.

Answer:

Absorbance of light at all wavelengths