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B.C., Demoocritus theorizes the Atom
Democritus was an ancient greek philosopher. he hypothesised that if you kept citting an object, you would eventually get to an "uncuttable" particle. he believed that these were infinite particles and couldn't be broken down anymore. -
John Dalton theorizes the atom
John Dalton was an english scientist from the early 1800s. he contributed to the atomic theory by theorizing the billiard ball model of atoms. -
Sir william Crookes tubular experiment
William did not make a new theory about atoms, but he did do an interesting experiment. by setting up two electrodes and sending a charge between them in a vacuum, crookes saw a particle beam. this led to a revision of the atom model -
J.J. Thompson's theory
after crookes' discovery a scientist by the name of J.J. Thompson took over. he had the idea of holding a magnet to the ray. to his surprise, the ray attracted towards the positive side of the magnet! this meant that the beam had a negative charge. these negative charges became known as electrons. he named the positive particles in the ray protons. he then created the plum pudding atom model. -
Ernst Rutherford
John Rutherford was the student of Thomson, and sought to revise the puddong model of his teacher. he did a lot of research in the field of magnetics and thought very highly of one of his students, Niel Bohr. -
Niels Bohr's theory
Niles bohr was the student of Ernst Rutherford. He used an electron microscope to observe atoms. He discovered that electrons are constantly orbiting atoms. He called these orbits electron shells and found out how many electrons could be in each shell at the maximum -
Today's theory
by now we have slightly updated bohr's model. instead of having a constant orbit, we have concluded that electrons orbit in clouds around the positively charged nucleus -
B.C., Aristotle theorizes the atom
aristotle was very different from Democritus. he believed that everything was made up of the four elements: wind, fire, earth, and water. he thought that these were what made up the universe, and that Democritus was a joke.
