Beer's Law (Beer-Lambert Law):
The amount of energy absorbed or transmitted by a solution is proportional to the solution's molar absorptivity and the concentration of solute. In simple terms, a more concentrated solution absorbs more light than a more dilute solution does. The mathematical statement of Beer's law is A = εlc, where: A = absorption; ε = molar attenuation coefficient, l = path length (the thickness of the solution), and c = concentration of the solution.
This equation is also expressed as A=log(Io/I)=εlc.
In this document, we explain how this equation works.