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John Dalton (1766-1844) John was an English chemists who devolped the atomic theory. His theory was made in 1803. It stated three things: 1. All matter was composed of atoms 2. Atoms had differnet weights and composed of different things 3. There are three types of atoms

Dalton was born in Cumberland England. He found that he liked chemistry and liked studying gasses. He kepted a dairy where he kept his ideas and what he saw in the world, that is where he came up with the atomic theory. He made the finding in 1803 but his work wasn't published until 1805. He came up with the theory on his own without anybody else's help.



Atoms: The 90 natural types of atoms, but scientists have been able to make 25 more in labs. There are protons, neutrons and electrons that make up an atom, they all form together to make a nuclus(main part of the atom) Proton- postive Neutrons-nothing Electrons- negative Each element has a different number of Protons, Neutrons and Electrons. So their atomic numbers will be different.