The Modern Atom-    What's different?     Studies of the atom have surely come a long way from the times of Democritus, Dalton, and Mendeleev. Thanks to a compilation of brilliant minds, we have a much greater understanding of the modern atom. Through further discoveries, quantum mechanics has become greatly more complicated and diverse. The behavior of particles is now understood, protons and neutrons are no longer elementary particles, and multiple atom models exist simply to make different aspects of quantum mechanics more understandable. Further Electron Understanding: While the idea that electrons are negative and are found outside of the atom remains, quantum mechanics has further defined their behavior and where they are located in space. Albert Einstein discovered that electrons and photons can act like both waves and particles. Physicists also discovered that electrons are located and in areas called electron shells around the nucleus. These shells have shapes as shown to the right and the direction of an electron's spin can even be found. Elementary Particles: The original elementary particles were electrons, neutrons, and protons. Through further research, dozens of other particles have been discovered. Bosons, gluons, neutrinos, gravitrons, and quarks are just a few names of the many new elementary particles. Much has yet to be discovered about these particles but evidence of them has been proven through particle detectors and particle colliders. Most of what is known about these particles is that many of them help make up greater particles like neutrons and protons and the elementary particles are also responsible for different properties the particles may have. For example, gravitrons are believed to be responsible for the gravitational force between subatomic particles.