3: The Electrons
This following text link describes the very basic arrangement of electrons in an atom: Electrons
For a more fundamental understanding of the distribution of electrons, please watch the following videos. It will help you to get through the upcoming units of this course.
The first video describes the distribution of electrons in the atom according to the Bohr model and the quantum mechanical model. It explains what an atomic orbital is. It introduces the organization of electrons in energy shells and subshells (and relates them to the periodic table) as well as electron configurations, which will be explained further in the follow-up video.
Orbitals | Electronic structure of atoms | Chemistry | Khan Academy (13:37 min)
The second video follows up on the previous video explaining the relationship between orbitals, electron configurations and the periodic table.
More on orbitals and electron configuration | Chemistry | Khan Academy (14:30 min)
The last follow-up video exceeds the content of this brush-up course. But if you ever need to understand electron configurations of more complex elements, check it out.
Electron Configurations (by Khan Academy, 10:04 min)