Students learn about the quantization of a charge, investigate spectral lines, and learn about Bohr’s model. The wave and particle nature of light is explored, Schrodinger wave equation is introduced non-mathematically, and the dual wave and particle nature of electrons is also discussed. Students learn about the strong force and Feynman diagrams. They explore radioactive decay and half-life using randomly tossed marked cubes. They are introduced to Einstein’s equation and use it to calculate energy liberated by the conversion of mass. Students also explore nuclear fission and fusion reactions.