-
350
Aristotle
Made the method for gathering scientific facts. This was the basis for all scientific work to come. -
460
Democritus
Democritus was a Greek philosopher who came up with the idea of atoms. He asked the question, " How many times can you break something in half before it becomes to small to break anymore?" He called the basic matter principles, atoms. -
Antoine Lavoisier
He is often called the Father of Modern Chemistry. He was the first person to discover that water was made up of hydrogen and oxygen. He was also the inventer of the analytical balance, and said that elements were neither created nor destroyed. -
John Dalton
John Dalton was the next scientist in 2000 years to experiment more with the idea of the atom. He experimented with different chemicals, and found that matter did seem to be made up of something smaller. Came up with the first atomic model. -
Henri Becquerel
Henri Becquerel discovered radioactivity while investigating uranium, and other radioactive substances. -
J.J. Thompson
Was the first scientist to discover the electron. He used this knowledge to create the Plum Pudding Model, the next atomic model. -
Marie and Pierre
Did lots of research on radioactive elements and marterials. They were the first people to discover the elements radium and polonium. -
Max Planck
Max Planck's research stated that energy was not a continuous and flowing entity, but rather is carried in very small units. He named these units quanta. His work provided a new understanding for light and radiation. -
Robert Millikan
Using his oil drop experiment, Robert Millikan was able to effectively measure the charge of an electron, and come up with an equation. In doing so, he also confirmed Thomson's hypothesis on electrons. -
Ernest Rutherford
Ernest Rutherford's atomic theory stated that an atom had a central positive nucleus that was surrounded by negatively charged, orbiting electrons. His model showed that the majority of the mass of an atom, was in the nucleus. -
Niels Bohr
He applied quantum theory to Rutherford's atomic structure by assuming that electrons travel in stationary orbits. This led to his calculation of possible energy levels of electrons. With this information he made the planetary model. -
Henry Mosely
Mosely was the first to use an X-ray to study the structure of atoms. His studies allowed for more accurate atomic numbers, and a more accurate periodic table. His work made the modern periodic table be based on atomic numbers. -
Werner Heisenberg
Werner is best known for his Uncertainty principle. This principle restricts the accuracy that some atoms can be determined. -
Erwin Schrodinger
He created the quantum mechanical model for the atom. The model doesn't predict the exact path of electrons. It shows a cloud around the nucleus of an atom. Where the cloud is thickest, that is where you are more likely to find electrons and vice versa. -
James Chadwick
James ChadwickJames Chadwick proved that the atomic nucleus contained a neutral particle which had been proposed more than a decade earlier by Ernest Rutherford. He discovered the neutron.
