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Democritus
Democritus thought that if you cut an object so many times that it would get so small that you could not cut it anymore. He called the smallest particle an atom. -
Dalton
Dalton's theory was that all substances are made of atoms, and atoms join with other atoms to make new substances. He also claimd that atoms of the same type were exactly the same, but atoms that are of different types were completely different. -
Roentgen
Roentgen was using a CRT when he dicovered the first X-ray. He saw that nearby chemicals glowed and some of the rays were not deflected by the magnetic field. -
Thomson
Thomson claimed that there are particles inside of an atom. He also discovered that electrons are part of an atom. -
Rutherford
Rutherford theory stated that atoms are soft "blobs" of matter. He tested his theory by conducting the gold-foil experiment. In this experiment the particles passed through gold in a straight line. -
Bohr
Bihr came up with the idea that the electrons of an atom move around the nucleus in a certain path. His model was called the ladder model. -
Schrodinger
Schrodinger proposed the "Electron Cloud Theory". He identified this as a location for potenital movement. -
Chadwick
Chadwick contributed to the atomic theory by discovering the make-up of the atomic nucleus. The nucleus of an atom is made up of protons and neutrons. -
Lawrenece
Lawrenece was the first to discover that radiation can be used to locate disease/cancer in the body and get rid of it. He also presented a machine to use the radiation. -
Fermi
Fermi conducted the first chain reaction that caused a realese in energy from the atomic nucleus. -
Modern Atomic Theory
The modern atomic theory states that atoms are constant. A chemical can not alter, destroy, or create an atom. Atoms can form together to create elements, but the atomic structure is always the same. Atoms of different elements can make compounds.
