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democritus
democritus proposed the idea of the existance of atoms, he thought that diferent substances were made of atoms that had different characteristics -
John dalton
Five main points of Dalton's atomic theory are
1.Elements are made of extremely small particles called atoms.
2.Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.
3.Atoms cannot be subdivided, created, or destroyed.
4.Atoms of different elements combine in simple whole-number ratios to form chemical compounds.
5.In chemical reactions, atoms are combined, separated, or rearranged -
thompson
thompson theorized that atoms were made of negatively charged electrons, or "plums", surrounded by a positivly charged "pudding" -
hanatro
hanatro proposes the existance ofan atoms nucules -
rutherford
rutherford experiments and states that atoms have a positivly charged nucleus with negetivly charged electrons moving randomly around it -
bohr
bohr proposes that the electrons move around the nucleus in an orbit at fixed distances from the nucleus -
shrodinger and hiensberg
these two help to form the electron cloud model where the nucleus has protons and neutrons and has a cloud surrounding it wher you are likely to find electrons, the denser the cloud, the more likely you are to find an electron -
chadwick
chadwick confirms the existence of neutrons, and that nuclei contain them
