Do you want to describe the microscopic world of atoms and nuclei? Well, classical physics isn't going to cut it. You'll need quantum physics to explain things like atomic energy levels, photons, and the wavelength of electrons.
Light can have wave-like or particle-like properties depending on the experiment being done. These "particles" of light are called photons. In this tutorial you'll learn about photon energy and momentum.
Sometimes people draw atoms like little solar systems, but they're way stranger than that. In this section you'll learn how electrons can have wavelengths, jump orbitals, and emit photons while in an atom.