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410
Democritus
This Greek Philosopher suggested that if you break something so small it wont be able to break any smaller. -
410
Aristotle
Aristotle disagreed with Democritus' theory and made a generalised theory that the world is made up of fire, water, earth, and air. -
Robert Boyle
Robert Boyle saw Aristotle's theory and thought that it's concept was werid. So he made a new theory where he purposed something new called an element. He described an element to be a substance that can be broken down any further with chemicals methods. -
Isaac Newton
Isaac Newton suggested that atoms were held toghther by attraction or forces. He also stated that atoms are always moving. -
Joesph Priestly
He was th one to find the elements Oxygen and Carbon Dioxide. His work was key to the development of the atomic theory. -
Antoine Lavoisier
Antoine Lavoisier or "the father of modern chemistry" is the one to state the law of conversion of mass. He said that matter can be different shape and form but the mass will always be the same. He also wrote down the first elements. -
Dmitri Mendeleev
Dmitri was the first one to make a draft of the periodic table and sort them by atomic weight. -
J.J Thomson
He discovered electrons.He reasoned that all elements have electrons and also atoms have no electric charge so there must be positively charged particles later to be known as protons. -
Niels Bohr
He thought electrons surrounded the nucleas in specific ways or energy levels.He named these shells he also noticed that only a specific amont of electrons can be in each shell. In the first shell 2 electrons, secound can have eight, and the third shell eight electrons. -
Ernest Rutherford
Ernest was the one to discorver the nucleas. He theorized that because the nucleas is positively charged electrons must orbit in.
