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Period: 450 to
Timeline
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465
Democritus- (BC)
In 465 BC Democritus was the first philosopher to suggest the atom. He comprised the atoms to be indivisible and industructable. -
Antoine Lavoiser
Lavoisier worked and did research on things like combustion, respiration and the calcination of different metals in 1772. He conducted a lot of research that helped get rid of the old theories about the combustion principle aka Phlogiston. Lavoiser gave new and improved explanations to these processes. He came up with many ideas about acids, bases and salts that made more sense. He also introduced a new chemical element in a more modern way and showed how it could be implemented by making the fi -
John Dalton
He proposed that atoms are indivisible, identical, atoms combine in whole numbers, and that they cannot be destroyed. Other wise known as the atomic theory. -
Max Planck
Main contributor to the quantum theory. Planck's hypothesis that energy is radiated and absorbed in discrete "quanta" precisely matched the observed patterns of black-body radiation. -
Dmitri Mendeleev
Dmitri Mendeleev- 1860 Mendeleev published his periodic table of all known elements and predicted several new elements to complete the table. Only a few months after, Meyer published a virtually identical table. Some consider Meyer and Mendeleev the co-creators of the periodic table, but virtually everybody agrees that Mendeleev's accurate prediction of the qualities of what he called ekasilicon, ekaaluminium and ekaboron qualifies him for the majority of the credit for the table. -
Eugen Goldstein
Goldstein contributed greatly to the study of cathode rays. He discovered protons with the experiments he did with cathode rays which would knock electrons of atoms and attract them to a positively charged electrode. 1886 he found the particles that are positively charged. -
J.J. Thomson
In 1894 JJ Thomson began to study cathode rays. Cathode Rays are glowing beams of light that follow electric discharges inside a vacuum tube. JJ Thompson created more efficient equipment and methods . When the rays went through the vacuum, thompson had the ability to measure the angle at the time they were deflected and was able to find ratio of the electrical charges to the mass of the particles. Thompson found out that the ratio was the same no matter what type of gas was used, all of this i -
Henry Mosley
In 1913 he discovered the xray. He observed and measured the X-ray spectra of various chemical elements obtained by diffraction in crystals -
Ernest Rutherford
Ernest is widely credited with first "splitting the atom" in 1917 in a nuclear reaction between nitrogen and alpha particles, in which he also discovered (and named) the proton. Him and James Chadwick discovered the neutron in 1932. -
Robert Millikin
In 1923 Robert Millikan was most famous for his oil drop experiments, while he was doing this he determined the electrical charge of the electron, he also had a lot of involvement in many major developments in radio and in other areas of electronic technology. His research and experiments on the electron was an important factor in opening up the door to the electronics revolution. For his discoveries and conribution to science he won the noble prize in 1923. -
Erwin Schrödinger,
an Austrian physicist, took the Bohr atom model one step further. Schrödinger used mathematical equations to describe the likelihood of finding an electron in a certain position. This atomic model is known as the quantum mechanical model of the atom. -
Niels Bohr
He is most known for helping out with the Quantum Theory. He contributed to modern physics was the atomic model.The atomic model showed that the atom is a small positively charged nucleus that is surrounded orbiting neutrons. In 1930 Bohr contributed to the Liquid Droplet Theory. -
James Chadwick
In 1932 James Chadwick discovered the neuron. He showed that in the reaction, a neutral particle with a mass about the same as a proton, was emitted. -
Robert Boyle
Founder of boyles law, which is an experimental gas law which describes how the pressure of a gas tends to decrease as the volume of a gas increases. He is also a main contributor to modern science
