Atomic Structure By christinabechly Period: Oct 25, 1700 to Oct 25, 2000 atomic structure Oct 25, 1793 John Dalton-- Wrote book "Meteorolgical Observations" Oct 25, 1897 JJ Thomson-- Discovered the electron Oct 25, 1903 Marie and Piere Curie-- Discovered polonium and radium Discovered polonium and radium Oct 25, 1911 Antoine Lavoisier-- Described atom having a central positive nuceus surrounded by negative electrons. Oct 25, 1932 James Chadwick-- Discovered unknown particle in atomic nucleus.