Key Events in our Understanding of the Structure of the Atom and Matter

Timeline created by l26 in Science and Technology

Event Date:	Event Title:	Event Description:
07/30/1704	Isaac Newton	Proposed a mechanical universe with small solid masses in motion.
01/01/1777	Antwan Lavoisier	Lavoisier formulated the law of conservation.
08/03/1791	Joseph Priestly	First to isolate elemental oxygen
01/01/1896	Henri Becquerel	While studying the effect of x-rays on photographic film, he discovered some chemicals spontaneously decompose and give off very pentrating rays
08/06/1897	JJ Thomson	For years scientists had known that if an electric current was passed through a vacuum tube, a stream of glowing material could be seen; however, no one could explain why. Thomson found that the mysterious glowing stream would bend toward a positively charged electric plate. Thomson theorized, and was later proven correct, that the stream was in fact made up of small particles, pieces of atoms that carried a negative charge. These particles were later named electrons.
01/01/1932	James Chadwick	Discovered the Neutron
01/01/1935	The Interaction of Elementary Particles	Sumi Yukawa theorized that protons and neutrons in the nucleus attract one another by exchanging mesons.
12/02/1942	Enrico Fermi	Enrico Fermi achieved the first self sufficient chain reaction and thereby initiated the controlled release of energy. In doing so he helped take the first major steps towards making feasible, the building of the atomic bomb.
01/01/1945	The Quantum Theory	Wolfgang Pauli's came to the conclusion that no two electrons in an atom can have the same four quantum numbers
04/12/1989	Marie Curie's Hypothesis	Marie’s hypothesis was revolutionary as it shifted the scientific understanding of that time. Before her hypothesis scientist believed that the atom was indivisible and undivided however through her hypothesis which stated that: "The emission of rays by uranium compounds could be an atomic property of the element uranium--something built into the very structure of its atoms." She realised and proved that there was a complex inner structure or immense energy stored in atoms