Molecules make up everything around us and they are very, very small. But those molecules are made of atoms, which are even smaller. And then those atoms are made up of protons, neutrons and electrons, which are even smaller. And protons are made up of even smaller particles called quarks. Quarks, like electrons, are fundamental particles, which means they can't be broken down into smaller parts. Or can they? In this episode we parse out the subatomic by talking with a physicist from Fermilab. We also hear how scientists' love for glass tubes aided in the discovery of electrons. Our Moment of Um tackles this puzzler: why is chocolate poisonous to dogs? All that and a smoking hot Mystery Sound.