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Democritus
Democritus thought that any object could be divided into smaller and smaller pieces. He named the theoretical smallest piece 'Atomos' meaning not to be cut.
Bohr
Bohr proposed that the electrons orbit the nucleus almost like how the planets orbit the sun, he proposed that the stronger the charge on the atom, the closer it orbits the nucleus.
Thompson
Thompson was the firs person to theorize that atoms are made of smaller particles. He thought that atoms were made of a positively charged substance with negatively charged electrons around them.
1803
1908
300 B.C
1913
400 B.C
Rutherford
Rutherford conducted an experiment and theorized that atoms have a densely packed center with positively charged electrons and negatively charged electrons around the nucleus which is what he called it.
1897
0 A.D
Dalton
Dalton conducted a number of experiments and accepted that atoms do exist. They are too small to see and cannot be destroyed.
Aristotle
Aristotle proposed that everything was made of only four elements, fire air, water and earth.