Hi! I’m Democritus! Everyone knows the infallible truth of the four elements, but I took it one step further by thinking about what those elements are made of. You’re going to love the name: Atoms! Aren’t they cute? Each type of atom is the same, but they all have different little bits on them. Iron, for example, is all rough and sticks together, but water is smooth and round and flows nicely! Time to shut down all the other atomists, I’ve figured it - Don’t listen to that old fool’s drivel! He doesn’t know what he’s talking about, but I do! Are you ready for Dalton’s Irrefutable Laws of How the World Works? Atoms of different substances are different! They have unique masses and sizes, and while Democritus was right in saying that atoms are all indivisible, invisible balls, he greatly overestimated the number of elements there were. I’ve discovered what I call compounds, which behave like new elements but are actually just existing elements joined together in definite proportions. Hey, maybe that’s a better name… The Law of Definite Composition! I’ve also found that creating these compounds never creates or destroys matter. I’ll call this one the Law of Conservation of Matt - Indivisible, my foot! I’m Joseph Thomson, and I used some fancy new tech to find these tiny negatively charged corpuscules. You see, my idea is that there is a positively charged sphere with a bunch of the corpuscles in it, like some kind of, I don’t know, plum pudding. The charges all balance out, leaving the atom neutral. Now, you may be wondering, how did I find these dashingly named corpuscules? Well, I was playing around with cathode rays and found that they had a negative charge, and furthermore that the mass-to-charge ratio (and therefore the mass) was nearly two thousand times smaller than that of a hydrogen atom! And even though I changed the cathode material, I got the same results. Therefore, these corpuscules must be in all atoms. You’re just missing one thing, J.J. My experiments show that there must be a concentration of positive charge at the center of the atom, not just diffused about it. When I shot some alpha-particles at thin sheets of gold foil, a few were deflected quite a bit more than your model would predict! I call these centers protons, and I think a better name for your corpuscules would be electrons, no? I just have one thing to add: There aren’t only protons in the nucleus. I’ve found some neutrally charged particles, or neutrons, that also clump together in the center of the atom. Now, what would be the best thing to do with my knowledge of nuclear physics? Woah… what happened here? Well anyways, I have a few problems with Rutherford’s planetary model. The orbits he described would all end up crashing into the nucleus, and that would be very bad if you like things to exist. However, I’ve theorised stable orbits for the electrons so that they don’t randomly lose energy. They can still absorb and emit discrete quanta of energy in the form of radiation, but they'll always jump to an adjacent shell. If an electron loses energy, it will jump to a lower orbital, closer to the nucleus, and if it gains energy, it will jump to a higher orbital. Because these orbitals are concentric circles, they naturally decrease in size and so only a certain amount of electrons can be in each shell. Haha! Imagine being able to know where something is! Indeed! As my friend Heisenberg found, the more certain you are of a quantum object’s velocity the less certain you are of the position. I’ve postulated that there are actually just clouds of probabilities surrounding an atomic nucleus, areas where you are likely (but not guaranteed!) to find an electron. Now, I’m going to see what other poor animals I can stuff in radioactive boxes. Toodles!
