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400 BCE
Aristotle
There was mass of insanely small size everywhere. -
400 BCE
Democritus
The name of his model was the Atomus, he knew nothing was smaller than an atom and an atom couldn’t be divided. -
John Dalton
The name of his model was the solid sphere model. His idea was all elements were made of same atoms and mass. -
Dmitri Mendeleev
He created the first periodic table and the elements were sorted by atomic mass. -
J.J. Thomson
His model was the plum pudding model, it had a sphere of positive charges with negative charges spread throughout. -
Ernest Rutherford
The name of his model was the nuclear model. He believed all atoms were empty space except for the nucleus which was dense and made up the atom. -
Henry Mosely
He discovered the number of protons is different in each element, which makes the atomic number different. -
Niels Bohr
He gave his model the name “Bohr’s model”, this stated that electrons are negative particles that orbit the nucleus at different levels. -
Schrodinger and Heisenberg
This was the electron cloud model, it showed that the nucleus is surrounded by an electron cloud where the electrons travel but not on a set orbit. -
James Chadwick
He discovered the neutron and this contributed to the creation of the atomic bomb and nuclear fission
