Light as a Ruler

A beam goes into a coloured solution and a weaker beam comes out. Topic 3.11 told you which wavelength to send. Topic 3.12 told you what one photon does when it arrives. This topic turns those two facts into a measuring instrument — because absorbance is linear in concentration, and a straight line is a ruler you can read backwards.

8 STEPS · 6 QUICK CHECKS · A = εbc · λ_max = 620 nm · UNIT 3 CLOSER · v1