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Jan 2, 1001
Aristotle
The greek man thought that atoms were made of earth, wind, fire, and air. He convinced the people because of the lack of technology and the he thought that you needed something hot, cold, wet, dry. -
Jan 1, 1417
Democritus
The 400 B.C man theory was not discovered until 1417. He believed that all matter consisted of extremely small particals named atoms (Greek atomos "uncut"). -
John Dalton
John was born in England in 1766. He was a teacher who did experiments in his spare time. He believed that the atom had no internal structure. He pictured them as tiny and indestructible. He used wooden spheres to represent the atoms of differeent elements.
1)All elements are composed of atomes.
2)All atoms of the same element have the same same mass, and atoms of different elements have different masses.
3)Compounds contain atoms of one or more elements -
J.J Thomson
Joseph John Thomson used electric currents to learn more about atoms. Thompson knew atoms were neutral, so there must be a balance of negative and positive particles. The new model is referred to as the Plum Pudding Model. This Model was soon proven wrong. -
Hantaro Nagaoka
He believed that an atom has:
*A very massive nucleus
*Electrons revolving around the nucleus, bound by electrical forces *Explained the rings os Saturn -
Ernest Marsden
One of rutherfords sudents, they had simular ideas.
But he would soon help elucidate something of value to all chemists: the internal structure of the atom. This was done by observing the path of particles that was one of Rutherford's more famous experiment, "gold foil experiment," -
Ernest Rutherford
Rutherford came up with his own physical model for subatomic structure, as an interpretation for the unexpected experimental results. The atom is made up of a central charge surrounded by a cloud of orbiting electrons. In a paper, Rutherford only commits himself to a small central region of very high positive or negative charge in the atom. -
Bohr
Bohr worked with Ernest Rutherford. Thier atom model was sooner neamred the Bohr-Rutherford Model. The model's key success layed in the explaination the Rydberg formula for the spectral emission lines of atomic hydrogen . His experiment was the meth problems and equations he used. -
Louis de Broglie
Broglie believed that atoms were waves. "With every particle of matter with mass m and velocity v a real wave must be 'associated" -
Erwin Schrodinger
Edwin Schrodinger said that electrons being distributed within an electron configuration of shells and energy levels, they were arranged in orbitals which were systematically distributed within Electron Clouds. He published his revolutionary work relating to wave mechanics and the general theory of relativity in a series of six papers. -
James Chadwick
Chadwick research focused on radioactivity. Chadwick proofs the existence of the neutron in 1932 what started up the research in nuclear physics.
