Atomic Timeline
John Dalton 1803 
Greek Philosopher
JJ Thomson 1897 
English Chemist: Proposed a modern theory of the Atom
Ernest Rutherford 1911 
English Physicist
Democritus 400 B.C. 
Niels Bohr, 1913 
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thought that atoms are tiny, uncuttable, solid particles that are surrounded by empty space and constantly moving at random
Introduced the idea of atoms being the basic building block
- Matter is made up of atoms that are indivisible and indestructible.
- All atoms of an element are identical.
- Atoms of different elements have different weights and different chemical properties.
- Atoms of different elements combine in simple whole numbers to form compounds.
- Atoms cannot be created or destroyed. When a compound decomposes, the atoms are recovered unchanged.
Announced that atoms were made of smaller particles and made the discovery of electrons
He found out that the atom is made up of mostly space but the mass is in a central positive charged nucleus
Erwin Schrödinger, 1926 
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He discovered that electrons moved around the nucleus but only in a specific orbit based on energy levels
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Discovered how to calculate the amount of electrons or energy levels of electrons in an atom
