The Atomic Theory Timeline

By: Jessica Jang

Democritus was the first to think that all matter was made of indivisible elements. He was also known to be the ‘father of modern science’. He

believed that it was impossible to destroy atoms, and that there were many different kinds of atoms. This was when the later to be known as ‘The Atomic

Theory’ started.

442 BC:

John Dalton discovered The Atomic Theory.

http://www.youtube.com/watch?v=IdSUqsq1yY8

1803:

Wilhelm Rontgen discovered that some chemicals would glow under cathode rays. This was the first discovery of X rays.

http://www.youtube.com/watch?v=0oy0fYeV764

1896:

JJ Thomson was the first to discover electrons.

http://www.youtube.com/watch?v=azXS0q3r9fY

1898:

Albert Einstein made a hypothesis about the particle of light. This is the base of nuclear energy. The main use of nuclear energy is to produce electricity. This is done by fission (when uranium atoms split). This makes heat, which makes steam, which is used to make electricity.

1905:

Robert Millikan was the first to measure an electron for its charge. This is called an elementary charge. He did this through

an experiment, the ‘Oil Drop Experiment’.

http://www.youtube.com/watch?v=XMfYHag7Liw

1908:

Ernest Rutherford has made a theory on the structure of atoms, what they look like. He was

the first one to discover the atomic nucleus.

1909:

Erwin Shrodinger discovered that electrons move in the form of a wave. The Shrodinger Equation is named after him. This

equation is required for quantum mechanics.

1926:

Irene Curie and Frederic Joliot-Curie discovered that it’s possible to create artificial radioactive elements. This means that it is very well possible to change the atoms in matter.

1934:

Otto Hahn and Lise Meitner were the first to discover nuclear fission. Nuclear fission is what creates energy, through the

separation of uranium atoms.

1938:

The Atomic Theory Timeline:

442:Democritus

1803:John Dalton

1896:Wilhelm Rontgen

1898:JJ Thomson

1905:Albert Einstein

1908:Robert Millikan

1909:Ernest Rutherford

1926:Erwin Shrodinger

1934:Irene Curie andFrederic Joliot-Curie

1938:Otto Hahn andLise Meitner

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http://www.softschools.com/timelines/atomic_theory_timeline/95/ http://www.worldsfamousphotos.com/2007/03/28/first-x-ray-1896/

http://dmr-astronomersclub.blogspot.ca/2012/10/electron-definition.html http://www.olympusmicro.com/primer/lightandcolor/particleorwave.html

http://www.westinghousenuclear.com/Community/WhatIsNuclearEnergy.shtm http://oldeloohuis.com/nuclearfusion.html

http://www.123rf.com/photo_2481145_atom-with-electron-orbits.html

http://kjohnsonnz.blogspot.ca/2011/03/ernest-rutherford-new-zealander-who.html

http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec14.html

http://germanhistorydocs.ghi-dc.org/sub_image.cfm?image_id=2112

http://www.universetoday.com/60058/democritus-atom/ http://commons.wikimedia.org/wiki/File:Democritus_by_Agostino_Carracci.jpg

http://the-history-of-the-atom.wikispaces.com/John+Dalton

http://en.wikipedia.org/wiki/Wilhelm_R%C3%B6ntgen

http://en.wikipedia.org/wiki/Robert_Andrews_Millikan

http://en.wikipedia.org/wiki/J._J._Thomson

http://www.rottentomatoes.com/celebrity/albert_einstein/

http://www.nobelprize.org/nobel_prizes/physics/laureates/1933/schrodinger-facts.html