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Dalton Creates His Atomic Theory
A chemist, known as John Dalton, figured that atoms (that are all alike) make up each element. Additionaly, he inferred that atoms of different mass make up different elements. As for what these atoms looked like, Dalton pictured small, smoothe, and solid balls (like a poolball, except for the size). -
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History of Atom Models: From Dalton to Now
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J.J. Thomson: Atoms and Electrons
A British scientist known as J.J. Thomson made a discovery. This discovery was the electron. It was through this discovery that Thomson realized a new model for the atom. Thomson's model showed an atom as a positively charged sphere, embedded with electrons. One could says that the Thomson model looked like a muffin with berries dispersed inside it. -
Hantaro Nagaoka: Solar System Atom
A Physicist by the name of Hantaro Nagaoka hypothesised a new model of the atom. This atom model had a large, positively charged sphere in the center. Continuing on from Thomson's model, this model too had electrons. Except, in this model, the electrons were revolving around the positively charged sphere (not unlike planets around the sun). -
Ernest Rutherford: Spacial Gap Atom
In 1911, a physicist called Ernest Rutherford put forth his idea on the model of an atom. Rutherford said that the majority of the atom is empty space. In the center was a tiny nucleus, positively charged. On the outside, Electrons revolved without pattern around the nucleus, the space in between the electrons and the nucleus being empty. -
Niels Bohr: The Onion Atom
Niels Bohr was a physicist who brought about a new kind of atom model. Bohr's atom had electrons that moved in specific layers/shells. Bohr also stated that, when electrons move from one shell to another, atoms either absorb or expel energy. Bohr's atom might resemble an onion, with its different layers that lead to the nucleus. -
Schroedinger: Cloud Tracer
Schroedinger, mostly known for his cat, has his own atom model. Schroedinger's atom model had a nucleus in the centre, composed of protons and neutrons. Complex regions were traced out by electrions, looking like oddly shaped clouds. -
Chadwick : Neutrons
In 1932, a physicist known as James Chadwick made a discovery. James' discovery explained why atoms weighed more than the total mass of the things that make them up. James' discovery is the neutron. -
Now: Electron Cloud
Finally, we come to the present model of the atom. We have gone through years of research, and so far this is the result. The atom, at present, is modeled as a cloud of negatively charged electrons, surrounding a nucleus. It has also been said that it is not possible to know the exact location of an electron at any given time.
