Teacher’s note: This student exemplar highlights the learning of Science in KAIS. The student, Andrew, self-driven his inquiry to learn the deeper concepts of Chromatography. Below is the student’s authentic writing and explanation.
Chromatography is a technique that is used to separate a mixture into its simpler components.
The basic principle of chromatography is that a solvent is used to dissolve the different components of a mixture. As the components are dissolved, they separate from one another based on the levels of attraction to the chromatographic medium.
First, a chromatographic medium, such as chromatography paper, is prepared. The medium exhibits different levels of attraction to each of the solutes. The solvent is then used to dissolve the mixture. The solution contains each of the different components of the mixture. The solution is then forced through the chromatography paper. The different components travel through the chromatography paper at different speeds, depending on their level of attraction. The substances that are less attracted to the paper move faster and farther downwards, while the substances that are more attracted to the paper move slower and less far. The substances have been separated and can then be analyzed individually.