-
440 BCE
Plato
said that all atoms break down into geometric shapes mathematically
http://abyss.uoregon.edu/~js/glossary/plato.html -
400 BCE
Democritus
theorized that mass is conserved in a chemical reaction
https://www.britannica.com/biography/Democritus -
Robert Boyle
he said that all elements are made of different kinds of atoms that organize into groups to create chemical substances
https://historyoftheatomictheory.weebly.com/robert-boyle.html -
Antone Lavoisier
found that mass is conserved in a chemical reaction
http://chemed.chem.purdue.edu/genchem/history/lavoisier.html -
The Alchemists
laid down the foundation of the Periodic Table
https://prezi.com/t50cihtay12m/alchemy-and-its-contributions-to-the-atomic-theory/ -
John Dalton
said that all matter is made of tiny, indivisible, indestructible atoms
https://www.britannica.com/biography/John-Dalton -
Amedeo Avogadro
hypothesized that equal volumes of gases contain equal number of molecules, if and only if temperature and pressure are the same
https://www.famousscientists.org/amedeo-avogadro/ -
JJ Thomson
found that all atoms are made of negatively charged electrons
https://www.khanacademy.org/science/chemistry/electronic-structure-of-atoms/history-of-atomic-structure/a/discovery-of-the-electron-and-nucleus -
Ernest Rutherford
found that an atom is mostly empty space with most of its mass in its nucleus
https://www.britannica.com/biography/Ernest-Rutherford -
Pierre and Marie Curie
discovered polonium and radium
https://www.britannica.com/biography/Pierre-Curie -
Albert Einstein
mathematically proved the existence of atoms
https://www.ans.org/news/article-969/albert-einstein-and-the-most-elemental-atomic-theory/#:~:text=Einstein%20also%20in%201905%20mathematically,use%20of%20statistics%20and%20probability.&text=Atomic%20theory%20says%20that%20any,always%20in%20random%2C%20ceaseless%20motion. -
Robert Millikan
he discovered that electrons have an electric charge and have a mass
https://www.nobelprize.org/prizes/physics/1923/summary/ -
Neils Bohr
said that electrons orbit around the nucleus
https://www.britannica.com/biography/Niels-Bohr -
Henry G. J Mosely
said that the atomic number is the number of positive charges in the atom's nucleus
https://www.britannica.com/biography/Henry-Moseley -
Dmitri Mendeleev
created the symbols of elements and organized them on periodic table based on weight of atom
https://www.britannica.com/biography/Dmitri-Mendeleev -
Erwin Schrodinger
used mathematical equations to say the likelihood of an electron to be in a certain position
http://www.abcte.org/files/previews/chemistry/s1_p6.html -
Werner Heisenberg
made the Uncertainty Principal, which says that a particle's position and momentum cannot be known exactly
https://www.atomicheritage.org/profile/werner-heisenberg -
