Atomic structure and the periodic table

• Chadwick discovered the neutrons in 1932.
• Rutherford discovered the nucleus
• JJ Thompson developed the plum pudding model in 1904
• In 1800s, Dalton stated that atoms were solid spheres.
• Neil Bohr adapted Rutherford's nuclear structure, and created the accepted model of today
• Groups tell us the number of electrons in the outer shell
• The period tells us how many shells there are