Answer:
The sentence from the third paragraph is: "The water then carries each color to a different level depending on the weight and size of the molecules in each dye."
This sentence explains how chromatography works in the context of the experiment with the black marker. When the water climbs up the paper and reaches the line drawn with the black marker, it interacts with the ink and separates it into different colors. The separation occurs because each color or dye in the ink has molecules with different weights and sizes.
As the water moves up the paper, it carries the individual colors or dyes with it. However, since the molecules of each dye differ in weight and size, they are carried to different levels on the paper. This separation creates distinct bands or patterns of color, allowing one to observe the different components that make up the supposedly "black" ink.
By analyzing the patterns and distances traveled by the colors, scientists can gain insight into the composition of the ink and the specific dyes used. This principle of chromatography, where substances are separated based on their molecular characteristics, is applicable not only in the case of markers but also in various scientific and forensic analyses.
Step-by-step explanation: