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Democritus
Democritus was a Greek philospher Who was from Abdera, Greece for 90 years. He studied philosphy and geometry, travelling across the world, and never getting married. He adopted ideas from his mentor, Leucippus, and began his own theories. He began his own theory in 465 BC, which stated a large amount of different things, including that it is impossible to destroy them, they can't differ in size, they always move and are invisible. Democritus was a very wealthy man, and died in 370 BC. -
John Dalton
John Dalton was born in 1766, and lived for 76 years. He was born into quite a poor family, but was extremely bright. Dalton was mainly interested in meteoroligy, which led to his wonderful theories. Dalton stated that elements were made from tiny particles called atoms. These were all identical in size and weight, and there was only one type of this in each atom. Dalton also stated that they can't be parted or destroyed. Dalton also discovered that atoms join with other's to create substances -
Ernest Rutherford
Ernest Rutherford was born on 30 October, 1871. Rutherford founded the Gold Foil Experiment, and found protons and neutrons. The Gold Foil Experiment is a trial where Rutherford directed Alpha Particles through gold foil. He found that most of the particles, which were positive, passed through the foil, however some came back. This brought the conclusion that an atom contains a positively charged nucleus. This nucleus has a large amount of mass but a miniscule amount of volume. -
Niels Bohr
Niels Bohr was born on 7 October, 1885. He concluded that electrons arranged in circles around the nucleus, with different amounts of energy in each circle. He proposed that protons and neutrons are located in the centre, while electrons can only be certain distances from the nucleus. These electrons orbit the nucleus as they gain or release a certain amount of energy. -
George Zweig
George Zweig was born on May 30, 1937. Zweig, with Murray Gell-Man, founded the quark, a composite particle that combines to be called hadrons, which make up protons and neutrons. -
JJ Thompson
JJ Thompson was born on 18 December, 1856, and found the electron. He did this by using cathode ray tubes, these have a piece of metal, an electrode at either side. These produce energy, and create a stream across the two cathodes. JJ Thompson was completing a experiment where he placed it in a magnetic field. his hypothesis was that the line would be straight, however because of like charges repelling, it bent, thinking there were electrons in there. He also made the plum pudding model.