Dylan Tao: Atomic Timeline

The Alchemists

500 BCE

The Alchemists broke down the chemical composition of the 4 elements of fire, water, earth, and wind. https://healthresearchfunding.org/alchemists-atomic-theory-explained/

Democritus

442 BCE

Democritus helped expand on the atomic theory that his mentor Leucippus had proposed. He also created the first model for the atom. https://atomictheorytimelineofscientists.weebly.com/democritus.html https://www.thehistoryville.com/atomic-theory-democritus-schrodinger/#:~:text=Democritus%20created%20the%20first%20atomic%20model%20%28a%20round,science%20of%20the%20atom%20and%20its%20generic%20makeup.

Plato

427 BCE

Plato introduced his own version of the atomic theory. https://treehozz.com/what-was-platos-atomic-theory

Robert Boyle

1661

Robert Boyle claimed that everything was composed of small particles of a single universal matter. https://www.britannica.com/biography/Robert-Boyle

Antoine Lavoisier

1789

Antoine Lavoisier discovered the Law of Conservation of Mass. https://atomictheorytimelineofscientists.weebly.com/antoine-lavoisier.html

John Dalton

1803

John Dalton proposed a theory very similar to the one today and Leucippus' theory. https://atomictheorytimelineofscientists.weebly.com/john-dalton.html

Dmitri Mendeleev

1869

Dmitri Mendeleev made a Periodic Table that organized the elements into a table according to their atomic weights. https://period1dmitrimendeleev.weebly.com/contribution-to-atomic-theory.html

J. J. Thompson

Apr 30, 1897

J. J. Thompson discovered electrons and deduced that they were smaller than the atoms themselves. https://atomictheorytimelineofscientists.weebly.com/j-j-thomson.html https://www.history.com/this-day-in-history/jj-thomson-announces-discovery-of-electrons

Pierre and Marie Curie

1898

Pierre and Marie Curie discovered Polonium and Radium. Marie Curie also stated that the arrangement of the atom doesn't make that the atom radioactive but the atom itself is radioactive. https://atomictheorytimelineofscientists.weebly.com/marie-curie.html https://easierwithpractice.com/how-did-marie-and-pierre-curie-contribute-to-the-atomic-theory/

Albert Einstein

1905

Albert Einstein discovered that atoms truly exist. He also showed that electrons can leave metals through the use of light. https://atomictheorytimelineofscientists.weebly.com/albert-einstein.html

Robert Millikan

1909

Robert Millikan discovered and figured out the electric charge on an electron. https://atomictheorytimelineofscientists.weebly.com/robert-millikan.html

Ernest Rutherford

Dec 20, 1910

Ernest Rutherford discovered the existence of the nucleus and protons. https://atomictheorytimelineofscientists.weebly.com/ernest-rutherford.html

Neils Bohr

1913

Neils Bohr made the model of the hydrogen atom and discovered electrons. https://historyoftheatomictheory.wordpress.com/niels-bohrs-contributions-to-atomic-theory/

Henry G. J. Mosely

1914

Henry G. J. Mosely justified the chemical concept of the atomic number. https://treehozz.com/what-was-henry-moseley-contribution

Erwin Schrodinger

1926

Erwin Schrodinger contributed to the atomic theory by making an equation that calculated the energy levels of an electron. https://atomictheorytimelineofscientists.weebly.com/erwin-schrodinger.html https://thehistoryoftheatoms.weebly.com/erwin-schrodinger.html#:~:text=Erwin%20Schrodinger%20-%20The%20History%20of%20the%20Atoms,finding%20of%20an%20electron%20in%20a%20certain%20position.

James Chadwich

1932

James Chadwich discovered and confirmed the existence of neutrons. https://atomictheorytimelineofscientists.weebly.com/james-chadwick.html