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460
Democritus
Born in 460 BC Greece.Democritus didn’t exactly ‘discover’ anything. But he was the first person to come up with the idea that things are made up of smaller invisible parts. AKA Atoms. It proved that there were smaller invisible things in this world.This ‘discovery’ changed our view of the properties of atoms because he believed everything was composed of tiny particles. No one took this ‘discovery’ very serious but it wasn’t until the 1800s that scientist started to reinvestigate the structure -
Period: 460 to
Scientists who contributed to the Atomic Theory
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Period: 500 to
Timeline of the Atomic Theory
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Period: Jan 1, 1400 to
History of the Atom
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Robert Boyle
25 January 1627 in IrelandRobert Boyle was a major contributor towards the Atomic Theory because he helped develop a definition of an element. Definition: ‘Any substance that can be broken into two or more substances is not an element.’ But that wasn’t the only thing he did to contribute to the Atomic theory, he helped with “the death” of the four elements. -
Isaac Newton
Born in 25 December, 1642 EnglandIsaac Newton theorized a mechanical universe with small, solid masses in motion, he also recognized that there are forces between atoms and that they affect the chemical properties of matter. He assumed ‘that all atoms of an element were identical and atoms of one element could not be changed into an atom of another element’. The discovery by Isaac Newton changed our views of the atoms by suggesting that atoms are held together by force. -
John Dalton
Born in 6th September 1766 EnglandJohn Dalton was of the first people to develop an atomic model. He thought that the atom was the smallest possible component of matter. He also was the first one to attempt to create the table of atomic weights. John Daltons discovery change our view of the atom because it opened a new door to all these questions about how and why there are smaller invisible parts inside an atom. -
Antoine Lavoisier
August 26th, 1783 FranceAntoine Lavoisier’s contribution to the atomic theory was that he reproduced a likelihood of atomic mass. Antoine Lavoisier had the nickname ‘The Father of Modern Chemistry’. -
George Stoney
15th February 1826 in IrelandGeorge Stoney was most famous for claiming the term electron as the ‘fundamental unit quantity of electricity He had introduced the idea but no the word ‘electron’. -
Dmitri Mendeleev
8th February 1834 in RussiaDmitri Mendeleev was most famous for putting together the ‘Table of the Elements (aka the periodic table) by their atomic weight and grouping them into families with similar features. Dmitri Mendeleev discovered 63 of the elements on the periodic table. -
J.J Thomspon
18th December 1856 in EnglandJ.J Thomson discovered the electron. An electron is a stable subatomic particle with a charge of negative electricity. J.J Thomson discovered the electron when he was experimenting with currents of electricity inside empty glass tubes. J.J Thomas changed John Dalton’s atomic theory because JJ Thomson discovered that you could cut an atom. -
Max Planck
- April 23, 1858 Germany - Max Planck contributed to the atomic theory by using the Quantum theory. Max’s work played a part in the atomic theory by giving us the understanding of the atomic and subatomic processes. It wasn’t until 1900 Max Planck publicized his findings. And then in 19-5, Albert Einstein used Max’s quantum theory to explain the particle characteristics of light. -
Ernest Rutherford
Born 30th August 1871 in New Zealand.Ernest Rutherford published his atomic theory explaining the atom as having a central positive nucleus surrounded by negative orbiting electrons. This discovery changed our view of the atom by explaining that majority of the mass was concentrated in a minute, if it was in a positive charged region. -
Neils Bohr
Born 7th October 1885 in Denmark.Niels Bohr suggested that based on the ‘quantum theory’ that electrons can travel around an atomic nucleus in a motionless orbit. His other work led to the atomic theory because of the different energy levels in an atom. Neil Bohr changed the way we looked at Atoms by him discovering a basic structure of an Atom, which then prepared the way for Quantum physics. -
Erwin Schrödinger
August 12th, 1887 in Austria Erwin Schrödinger was most famous for using mathematical equations to illustrate the location and energy level of an electron. Erwin Schrödinger’s math equation to illustrate the location and energy level of an electron, H(psi) = E(psi). -
James Chadwick
20th October 1891 in England. In 1932, He discovered the Neutron. If you don’t know what a neutron is, a neutron help stabilise the protons inside the atom’s nucleus. James Chadwick discovered the neutron by cracking alpha particles into beryllium and then sending the released radiation into a paraffin wax, which is containing hydrogen atoms. -
Enrico Fermi
- September 29th 1901 Italy - Enrico Fermi was most famous for the development of the first nuclear reactor and his contributions to the development of the quantum theory. He was an Italian-American Physicist.
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Murray Gell-Mann
15th September, 1929 in AmericaMurray Gell-Mann is one the most important people who have contributed to the atom. He showed other scientists what makes up a proton, neutron and quarks.
