Have you ever come home after a long day, plopped down on the couch, and started watching CSI, Law & Order, or some other modern crime drama? Fast forward three-and-a-half hours and your eyes are still glued to the TV, mesmerized by that nonconformist investigator who miraculously puts bad guys away based on a satang-sized blood splotch hidden on a Persian carpet. It’s pretty cool to watch someone solve serious crimes with wit, intelligence, and science.
Well, our science materials teach kids to do just that – solve crimes using science and analytical thinking. In a lesson called Separating Solutes, middle schoolers use a laboratory technique called chromatography to free the individual substances that combine to create a mixture. That may sound complicated if you haven’t brushed up on chemistry in a decade or three, but it’s grounded in the fact that most things are actually combinations of multiple substances bonded together.
Think saltwater. When you go swimming in the ocean, you don’t see or feel grains of salt because the salt has been dissolved in the water. Try opening your eyes under water, however, and the burning sensation will tell you that salt is undoubtedly there.
Chromatography has become one of the most powerful weapons that modern crime stoppers have in their holster. The technique has been applied to help solve a range of crimes, from bank robberies to terrorist bombings. Each year, kids at schools in Kenan’s education network learn the science behind chromatography and then put the technique to the test to solve a simulated crime.
First, the kids learn how to separate dyes from different colored magic markers using paper chromatography. Doing so is simple – the kids draw a dot with each marker on a piece of chromatography paper (coffee filters work too) and place it in a beaker with water filled about 3 millimeters high. In only a few minutes, the individual dyes (solutes) that mix to form the colors separate as they come into contact with the water (solvent) moving through the paper. Rainbow-like patterns appear as the water moves higher and higher. The kids, moreover, observe that some dyes move faster because they are more soluble than others.
After grasping the basics, the kids graduate to the fun part when they become little forensic scientists tasked with identifying who wrote a forged check. The police have three suspects, all of whom were found with black pens. The kids are given a chromatogram (the pattern that forms on paper) from ink extracted from the check. Now they have to test each suspect’s pen to see if it matches the ink on the check. This is possible because all manufacturers use slightly different mixtures to make their ink, meaning each will produce a unique pattern on the chromatography paper. If they can find a match, it would provide powerful evidence for who committed the crime. This is the same technique used by forensic investigators to solve crimes, analytical chemists to test new pharmaceuticals, and environmental scientists to measure water pollution.
Separating Solutes demonstrates our fun, hands-on learning approach that builds kids’ foundational science knowledge and puts them on the fast track to a 21st century career. That’s not to say that all our kids are going to become CSI agents, but the skills and knowledge introduced through our 7th-9th grade science and math modules form the building blocks for future career opportunities.
And, who knows, maybe one of these kids will grow up to become Thailand’s version of a real-life Sherlock Holmes.
John DaSilva is the Director of Partnerships and Communications at Kenan Foundation Asia and can be contacted at [email protected]. To learn more about Kenan’s work to develop 21st century teachers who can deliver high-impact lessons like Separating Solutes, please visit us at www.kenan-asia.org/teacher-professional-development