This lesson has a summary about the structure of the atom and the atomic theory. The students will be able to know some history about how the electron, proton and neutron were discovered and characterized. Also the students will describe the use of spectroscopy to discover the structure and energy levels of electrons within the atom and the electron configuration. The students will be able to explain the use and meaning of the four quantum number. Also they will be able to work problems involving the electronic structure of the atom.