The Important Lesson

This page is about the most important thing you should learn from the story of Felix Hoffmann and the discovery of aspirin. What is this important lesson? The lesson is that everything is made from tiny molecules, and that molecules are made from atoms. The number of atoms, the kind of atoms, and the way the atoms are arranged in the molecules will determine what properties a substance made from those molecules will have. We call the kind and number of atoms and their arrangement in a molecule the molecular structure of a molecule. Scientists use chemistry to take molecules apart, and put them back together in different ways. This is how they create new molecules and therefore new substances with different properties from the original materials.

This is what Felix Hoffmann did. He took apart the molecules of salicylic acid and acetic anhydride, and put their atoms back together to make molecules of acetylsalicylic acid. He changed the structure of his molecules, and by doing so changed their properties. Today scientists have become skilled enough that they can take apart and reassemble molecules almost like Tinkertoys^® that children play with. The number of different molecules that could be made is limitless, and it only takes a little bit of creativity to put together new molecules that might be drugs to cure cancer, plastics that can stop bullets, or fuels that burn clean.

If you're planning on being a scientist who builds amazing new molecules, you can start practicing with two little activities we call Build Your Own Molecule and Designer Molecules: Esterification. Coming up next, we have another story of a scientist who changed the behavior of a pain reliever by altering its molecular structure. To find out what she did, follow the link below to "Polymers vs. Pain."

Next: Polymers vs. Pain