I may be totally wrong but I’ll make a guess to it being thermodynamics.
Answer: determines the age of sample Carbon-14 is used in radiocarbon dating and radiolabeling. Medically important, a radioactive isotope is carbon-14, which is used in a breath test to determine the ulcer-causing bacteria Heliobacter pylori
The radiocarbon age of a certain sample of unknown age can be determined by measuring its carbon 14 content and comparing the result to the carbon-14 activity in modern and background samples.
The answer is Thickness of solution.
The Beer-Lambert Law equation has the following form:
A=E×b×c
Where A is absorbance, E <span>is the molar absorbtivity, </span>b is the path length of the sample and c <span>is the concentration of the compound in solution.
</span>
<span>Lamber-Ber's law shows that the absorbance of a solution is directly proportional to the concentration of the species to be absorbed, as well as the length of the path. For example, if the length of the path is constant, the UV / VIS spectroscopy can be used to determine the concentration of the absorbent substance in the solution.</span>