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600 BCE
Buddhist Atomism
Four kinds of atoms, corresponding to the standard elements, are defined by this form of atomism. Each of these elements has a particular property, such as strength or motion, and in mixtures it performs a particular function, such as providing support or causing growth. -
500 BCE
Democritus's formulation of an atomic theory of the universe.
Democritus was a pre-Socratic philosopher of the Ancient Greeks. Democritus' idea was that everything consisted of "atoms" not physically seen but not actually incapable of separating; there is empty space between atoms; atoms are indestructible and have been and will still be in motion; there is an infinite number of atoms and all kinds of atoms of various shapes and sizes. -
450 BCE
Empedocles
Greek scholar named Empedocles proposed an idea that matter was made up of four different elements, Earth, Air, Fire and Water. Empedocles divide matter into four elements. such as Earth, Air, Fire and Water. -
400 BCE
Aristotle
Aristotle was an big part of ancient Greek philosophy. He made contributions to logic, metaphysics, mathematics, physics, biology, botany, ethics, politics, agriculture, medicine, dance and theater. He proposed that all matter was continuous and can be further divided infinitely into smaller pieces. -
800
Abu Musa Jabir Ibn Hayyan
Abu Musa Jabir Ibn Hayyan was an Arab scientist who lived in Persia (modern day Iran) during the 8th century. Jabir Ibn Hayyan's theories claimed that numerical values described the existence of and properties of elements. During the Middle Ages, many of his findings would influence future Arabian scientists and even European scientists. -
1250
Albert Magnus
German Catholic and Bishop of Albert Magnus. The element Arsenic, he found. By heating soap along with orpiment, he discovered it. He also assumed that compositions of matter and form were all natural things. -
Antoine-Laurent de Lavoisier
Antoine-Laurent de Lavoisier was a French nobleman and chemist who had a large influence on both the history of chemistry and the history of biology. Lavoisier is most noted for his discovery of the role oxygen plays in combustion. He recognized and named oxygen and hydrogen and opposed the phlogiston theory. Lavoisier helped make the metric system. He also wrote the first extensive list of the elements. -
Henry Cavendish
Henry Cavendish was a British natural philosopher, scientist, and an important experimental and theoretical chemist and physicist. Cavendish is noted for his discovery of hydrogen or what he called "inflammable air". He described the density of inflammable air, which formed water on combustion. Antoine Lavoisier later reproduced Cavendish's experiment and gave the element its name, "hydrogen". -
Dolton's atomic theory
John Dalton was an English chemist, physicist, and meteorologist. Dalton use the Law of Mass Conservation, Law of Constant Composition, and the Law of Multiple Proportions to help him come up with the atomic theory. He come up with three things for matter, matter is composed of tiny indivisible particles called atoms, all atoms of the one element are identical but are different from the atoms of other elements, and chemical reactions consist of rearranging atoms in simple whole number ratios. -
Avogadro's law
Amedeo Avogadro was an Italian scientist. He was most known for his contribution to molecular theory. It is now known as Avogadro's law. Avogadro's law states that equal volumes of gases under the same conditions of temperature and pressure will contain equal numbers of molecules. -
Periodic table of elements
Dmitri Mendeleev was a Russian chemist and inventor. He created the Periodic Law and created the periodic table of elements. He used it to correct the properties of some already discovered elements and he also predicted eight elements that were yet to be discovered. -
Discovered the noble gases
William Ramsay was a British chemist who discovered the noble gases. He received the Nobel Prize in Chemistry in 1904 "in recognition of his services in the discovery of the inert gaseous elements in air". Ramsay work on argon, helium, neon, krypton and xenon. Because of the discovery's it led the development of a new section in the periodic table. -
Discovery and identification of the electron
Sir Joseph John Thomson was an English physicist and Nobel laureate in physics. JJ was credited with the discovery and identification of the electron. He was known to discover first subatomic particle. Some of his contributions were to state that atoms consist of a large sphere of uniform positive charge embedded with smaller negatively charged particles. Also the total positive charge of the sphere equals the total negative charge of the corpuscles. -
Rutherford's discovery of Nucleus and Proton
Ernest Rutherford discovered the atomic nucleus and developed a model of the atom that was similar to the solar system. The model grew after it was modified with quantum theory. Rutherford was able managed non-radioactive atom to lose strength, forcing a single particle out . The particle had a positive charge, so it must have came from the nucleus. So he called the new particle a proton. -
Niles Bohr's Planetary Model
Niels Bohr was a Danish physicist who made several contributions to understanding atomic structure and quantum theory. Some of the contributions he stated were electrons move around the nucleus in fixed orbits. An electron in a particular orbit has constant energy; an electron can absorb energy and move to a higher energy orbit of larger radius; an excited electron can fall back to its original orbit by emitting energy as radiation; electrons can only exist in certain discrete energy levels. -
Schrödinger's equation
Erwin Schrodinger was a German physicist who developed a number results in the field of quantum theory. Some of his contributions were stated that electrons occupy orbitals, volumes of space around the nucleus with a high probability of finding the electron; energy levels are made up of energy sublevels; each sublevel contains a set of orbitals; No orbital can contain more than 2 electrons. -
Heisenberg's uncertainty principle
Werner Heisenberg was a German who took an interest in theoretical physicists. He applied a mathematical system to atomic physics it was called matrix mechanics.
Heisenberg also developed new theories in quantum mechanics about the behavior of electrons. The theory's were proven by previous experiments. He helped explain the movement of electrons. -
de Broglie hypothesis
Louis de Broglie was a French physicist who made major contributions to quantum theory. In his 1924 PhD thesis he assumed the wave nature of electrons and suggested that all matter has wave properties. This concept is known as the de Broglie hypothesis. -
The Dirac equation of antiparticles predicts
Schrödinger's equation agreed with only slow moving particles and therefore didn't alien with Einstein's theory of relativity. When finding a solution to this problem his derivation of relativistic wave equation implied the existence of a new form of matter, a mirror version of the matter currently known. This is called the antimatter. Therefore, Dirac's equation predicted the existence of antimatter. -
Carl Anderson's Discovery of 1st antimatter particle
In the year 1932 Caltech Carl Anderson discovered the anti particle of positron which is called positron. To do this he had to built a cloud chamber to determine the composition of cosmic rays, high-energy particles that rain down from space. For this discovery he won the Nobel prize for physics in 1936. -
Discovery of Neutron
James Chadwick was a prisoner of war in Germany for four years. When WWI ended he went back to England. When returning to England he rejoined his mentor Ernest Rutherford. Chadwick researched on radioactivity. He was able to determine that the neutron did exist and that its mass was about 0.1 percent more than the proton's. -
Cyclotron
A cyclotron is a type of particle accelerator invented at the University of California, Berkeley, by Ernest O. Lawrence in 1929–1930, and patented in 1932. A cyclotron accelerates charged particles outwards into a spiral direction from the middle of a flat cylindrical vacuum chamber. The particles are held by a static magnetic field in a spiral trajectory and accelerated by a rapidly changing electric field. The 1939 Nobel Prize in Physics for this invention was awarded to Lawrence. -
Discovery of antiproton
The antiproton was first confirmed experimentally by University of California, Berkeley physicists Emilio Segrè and Owen Chamberlain at the Bevatron particle accelerator in 1955, for which they were awarded the 1959 Nobel Prize in Physics. -
Discovery of antineutron
After one year of the discovery of the antiproton Bruce Cork, Glen Lambertson, Oreste Piccioni and William Wenzel discovered the anti neutron in Bevatron (Lawrence Berkeley National Laboratory).Antineutrons were created when antiprotons in the beam exchanged their negative charge with nearby protons, which have a positive charge. The antineutrons were detected through their annihilation reactions with neutrons and protons. -
Existence of subatomic particle
Physicists Murray Gell-Mann and George Zweig independently proposed the existence of subatomic particle know as quarks while working independently on a theory for strong interaction symmetry in particle physics. with the time physicist have able to fined other types of subatomic particles and find it lead to the creation of
standard model of particle physics
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Discovery of Anti-nuclei
By 1965, all three particles that make up atoms (electrons, protons and neutrons) were known to each have an anti-particle. The next big challenge was to create an anti-nuclei. This goal was achieved in 1965 with the observation of the antideuteron, a nucleus of antimatter. Teams of two physicists simultaneously discover this one at CERN and one at Alternating Gradient Synchrotron (AGS). -
First proton-antiproton collision
In 1960s Bruno Scheck proposed the 1st electron and position collision and after over coming many issues it was finally achieved in 1981 at Cern Super Proton Synchrotron (SPS). Simon van der Meer and Carlo Rubbia won the Nobel price for this discovery. By the year 1984 when it was shutdown, it had produced many important results, including indications that protons contain smaller constituents, ultimately identified as quarks and gluons. -
Discovery of Higgs boson
Higgs boson aka god particle first described by peter Higgs with the help of other physicist. Discovery of this particle suggests that the existence of Higgs field. According to this theory particles get their mass as a result of interaction with this Higgs field.
