Atoms - introduction: 4'40"
H, He, Li, Be, B: 2'47"
C,N,O,F: 2'12": 2'12"
Ne-Ca: 2'31"
Practice problems: Net charge, mass number, atomic number: 4'57"
Models of the atom timeline: 10'52"
Discovery of the electron: 11'08"
Discovery of the nucleus: 15'59"
Charge of an electron: 12'53"
Discovery of the neutron: 10'12"