1. The Atomic Theory Timeline
By: Jessica Jang

2. 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:

3. John Dalton discovered The Atomic Theory.
1803:

4. Wilhelm Rontgen discovered that some chemicals would glow under cathode rays. This was the first discovery of X rays.
1896:

5. JJ Thomson was the first to discover electrons.
1898:

6. 1905:
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.

7. Robert Millikan was the first to measure an electron for its charge
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’.
1908:

8. 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:

9. Erwin Shrodinger discovered that electrons move in the form of a wave
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:

10. 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:

11. Otto Hahn and Lise Meitner were the first to discover nuclear fission
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:

12. The Atomic Theory Timeline:
1938:
Otto Hahn and
Lise Meitner
1908:
Robert Millikan
1909:
Ernest Rutherford D D
1898:
JJ Thomson D D
442:
Democritus D
1803:
John Dalton
1896:
Wilhelm Rontgen D
1926:
Erwin Shrodinger D
1905:
Albert Einstein
1934:
Irene Curie and
Frederic Joliot-Curie

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