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460 BCE
Democritus
Developed the atomic theory of the universe. Democritus held that everything is composed of "atoms," which are physically, but not geometrically, indivisible; that between atoms, there lies empty space; that atoms are indestructible, and have always been and always will be in motion; that there is an infinite number of atoms and of kinds of atoms. -
460 BCE
Democritus
He was a Greek philosopher, mathematician, and polymath disciple of Leucippus, founder of atomism, and teacher of Protagoras. He was born in 460 BC, Abdera, Greece, and died about 360 BC in Greece. -
John Dalton
Was the first to adapts Democritu´s theory into the first modern atomic model. He hypothesized that the law of conservation of mass and the law of definite proportions could be explained using the idea of atoms. He proposed that all matter is made of tiny indivisible particles called atoms, which he imagined as "solid, massy, hard, impenetrable, movable particles¨. It was the first atomic model with scientific bases. -
John Dalton
He was a British naturalist, chemist, mathematician, and meteorologist. His works include the atomic model and his table of relative weights of the elements, which contributed to laying the foundations of modern chemistry. He was born on September 6, 1766, in Eaglesfield, United Kingdom, and died on July 27, 1844, in Manchester, United Kingdom. -
William Crookes
His discovery of the element thallium and his cathode-ray were noticed by physicists and chemists. This was fundamental in the development of atomic physics. He discovered plasma while playing with an experimental electrical discharge tube in which air is ionized by the application of a high voltage through a voltage coil. -
William Crookes
He was an English chemist, one of the most important scientists in Europe in the 19th century, both in the field of physics and chemistry. He was born on June 17, 1832, in London, United Kingdom, and died on April 4, 1919, in London, United Kingdom. -
J.J Thomson
The physicist who is credited for discovering the electron. He announces the discovery of the electron also examined positive rays, previously studied by Eugen Goldstein, and in 1912 he discovered how to use them in the separation of atoms of different masses. In turn, he discovered that neon has two isotopes, neon-20, and neon-22. -
J.J Thomson
He was a British scientist, discoverer of the electron, of isotopes, and inventor of the mass spectrometer. In 1906 he was awarded the Nobel Prize in Physics. He was born on December 18, 1856, Cheetham Hill, Manchester, United Kingdom, and died on August 30, 1940, in Cambridge, United Kingdom -
Ernest Rutherford
He thus set up his now-famous Gold Foil Experiment. He fired alpha particles with a positive charge to a gold foil. He said that there must be a positive center of the foil. He called this center the nucleus. Theorized the neutron. -
Ernest Rutherford
Also known as Lord Rutherford, he was a British physicist born in New Zealand. He dedicated himself to the study of radioactive particles and managed to classify them into alpha, beta, and gamma. Was born on August 30, 1871, in Brightwater, New Zealand, and died on October 19, 1937, in Cambridge, United Kingdom. -
Niels Bohr
He was able to answer why the electrons did not collapse into the nucleus. He developed the so-called theory of the atom and the model of the liquid atomic nucleus. he succeeded in showing that each electron rotates around the nucleus in an orbit without emitting any radiant energy. -
Niels Bohr
He was a Danish physicist who contributed to the understanding of the atom and quantum mechanics. He was awarded the Nobel Prize in Physics in 1922. Was born on October 7, 1885, in Copenhagen, Denmark, and died on November 18, 1962, in Carlsberg, Copenhagen, Denmark. -
Robert Millikan
He discovered that electrical charge is "quantized." This means that any value of the charge is an integer multiple of an elementary charge, that of the electron. It measured the electric force on a small charged drop due to an electric field created between two electrodes when the drop was in the gravitational field. Knowing the electric field, it was possible to carry out the determination of the accumulated charge on the drop. -
Robert Millikan
He was an American experimental physicist who won the 1923 Nobel Prize in Physics primarily for his work to determine the value of electron charge and the photoelectric effect. He also investigated cosmic rays. Was born on March 22, 1868, in Morrison, Illinois, United States, and died on December 19, 1953, in San Marino, California, United States. -
Henry Gwyn
He discovered the atomic number of each element using x-rays. Gave the quantitative justification of the concept of atomic number in Moseley's Law, which allows the rapid identification of an element knowing its atomic number, which means that when elements are ordered by their atomic numbers in ascending order. -
Henry Gwyn
He was an English physicist and chemist. His main contribution to science was the quantitative justification of the concept of atomic number by Moseley's Law. Was born on November 23, 1887, in Weymouth, United Kingdom, and died on August 10, 1915, in Gallipoli Peninsula, Turkey. -
Erwin Schrödinger
He was a revolutionary physicist that came up with the atomic model we use nowadays using Heisenberg´s principle. Also created wave mechanics or quantum mechanics. He discovered the fundamental equation of said mechanics. -
Erwin Schrödinger
He was an Austrian physicist, naturalized Irish, who made important contributions in the fields of quantum mechanics and thermodynamics. He received the Nobel Prize in Physics in 1933 for having developed the Schrödinger equation, shared with Paul Dirac. Was born on August 12, 1887, in Erdberg, Vienna, Austria, and died January 4, 1961, in Vienna, Austria. -
James Chadwick
He discovered that in the collision between alpha particles and beryllium atoms, neutral particles were obtained, with a mass approximately equal to that of the proton, which was called neutrons. Called Heisenberg Atomic Model. -
James Chadwick
He was an English physicist who was awarded the 1935 Nobel Prize in physics. It is mainly known for the discovery of the neutron. Was born on October 20, 1891, in Bollington, UK, and died on July 24, 1974, in Cambridge, UK.
