However, adsorption and absorption are sometimes confusing for students. These are two different 65 phenomena in chemistry. Adsorption is related to surface chemistry, while absorption, in this experiment, is connected to light absorption (absorbance), which is directly proportional to the concentration of the colored solution. Despite simple explanations, the lack of visualization of these phenomena can make them difficult for students to grasp. We demonstrate an activity that can demonstrate the two processes using common laboratory materials. In the experiment described herein, 70 students are introduced to and use the scientific method to study the adsorption properties of fish scales from white snapper (Macolor niger) in the presence and absence of Cu²⁺ ions, and the solution's color intensity in connection with smartphone colorimetry.