There's a charmed quark and a strange quark. This fact is experimentally well-known for example in quantum optics; see e. Mathematically, the average distance, or in this case the energy or probability of finding the electron, is just the square root of the wave property. Answer a 3 p Answer b 5 f Answer c 2s. Baez cautions, "there's no way to understand the interpretation of quantum mechanics without also being able to solve quantum mechanics problems — to understand the theory, you need to be able to use it and vice versa ". Niels Bohr then developed Planck's ideas about radiation into a model of the hydrogen atom that successfully predicted the spectral lines of hydrogen. Quantum mechanics models describe the possibility of placing electrons within an atom by describing the main energy level, orbital arbitrary level , and spin. Those items contain smaller particles: protons and neutrons in the nucleus and electrons orbiting around the outside, like a model of the solar system, known as the planetary model. This is the so-called fine structure of the spectrum, and it implies that there are additional small differences in energies of electrons even when they are located in the same orbital. Again, each orbital holds two electrons, so 50 electrons can fit in this shell.