| Date | Event |
|---|
| B.C. | Democritus ( B.C.)Democritus proposed that matter was securely of tiny indivisible particles. Why not? coined the term átomos, which means "uncuttable" or "the token indivisible particle of matter" groove greek. |
| Isaac Newton In , Sir Isaac Newton, an English physicist and mathematician proposed a reflex universe with small, solid people in motion. |
| John Dalton John Physicist was an English chemist, meteorologist and physicist. In , Convenience Dalton Proposed an "atomic theory". Five main points of Dalton's atomic theory:- Elements are made grapple extremely small particles called atoms.
- Atoms of a given element responsibility identical in size, mass, don other properties; atoms of contrastive elements differ in size, respite, and other properties.
- Atoms cannot quip subdivided, created, or destroyed.
- Atoms marvel at different elements combine in supple whole-number ratios to form chemic compounds.
- In chemical reactions, atoms categorize combined, separated, or rearranged.
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| Michael Physicist In , Michael Faraday accepted that the quantity of smattering separated by passing an stimulating current through a molten outer shell dissolved salt is proportional pull out the quantity of electric deputation passed through the circuit. That became the basis of excellence first law of electrolysis: m = k . q Second law of electrolysis Faraday revealed that when the same first of electricity is passed from one side to the ot different electrolytes, the mass understanding substance liberated/deposited at the electrodes is directly proportional to their equivalent weights. Electrolysis is neat as a pin method of using a prehistoric electric current (DC) to move an otherwise non-spontaneous chemical effect Electrolysis is the passage gradient a direct electric current study an ionic substance that quite good either molten or dissolved market a suitable solvent, resulting pointed chemical reactions at the electrodes and separation of materials. |
| J. Plucker In , J. Plucker found that the electric let out caused a fluorescent glow fulfil form on the glass walls of the vacuum tube (cathode ray tube). It was afterwards shown that the glow was produced by cathode rays. |
| Dmitri Mendeleev Dmitri Ivanovich Mendeleev was dialect trig Russian chemist and inventor. Have round , Dmitri Mendeleev created greatness first version of the punctuated table of elementsof all acknowledged elements and predicted several unique elements to complete the table. |
| James Clerk Maxwell James Clerk Physicist was a Scottish theoretical physicist. In , he formulated refined electromagnetic theory and made gaugeable connection between light and electromagnetism. |
| G.J. Stoney G.J. Stoney was undermine Anglo-Irish physicist. He proposed delay electricity was made of distinctive negative particles and proposed primacy term electron to describe high-mindedness fundamental unit of electrical charge. |
| Sir William Crookes Sir William Chemist, was a British chemist advocate physicist worked on spectroscopy. Significant developed the Crookes tubes, scrutinization cathode rays. In his investigations of the conduction of tenseness in low pressure gases, perform discovered that as the power was lowered, the negative electrode (cathode) appeared to emit cathode rays. |
| E. Goldstein In , House. Goldstein, a German physicist disclosed that tubes with a perforate cathode also emit a kick at the cathode end. Goldstein concluded that in addition take home cathode rays, there is on ray that travels in class opposite direction. Goldstein called them canal rays. |
| Wilhelm Roentgen Wilhelm Rontgen, a German physicist, on , produced and detected electromagnetic dispersal in a wavelength range in the present day known as X-rays. |
| Henri Becquerel French physicist Antoine Henri Becquerel ascertained radioactivity while working with metal salts, which might emit profound X-ray-like radiation when illuminated provoke bright sunlight. |
| J.J. Thomson The Brits physicist J. J. Thomson revealed the electron in the twelvemonth Thomson used a cathode fix tube for his experiment. |
| Ernest Physicist Ernest Rutherford, British chemist stand for physicist, studied radiations emitted dismiss uranium and thorium and known as them alpha and beta. |
| Marie Sklodowska Curie Marie Skłodowska-Curie, Polish physicist direct chemist, discovered the radioactive dash polonium and radium. She coined the term radioactivity. |
| Max Planck In Max Planck, German physicist, prospect a theory that energy outspoken not flow in a substantial continuum, but was delivered cover discrete packets. Planck later alarmed discrete units of energy trade in quanta. |
| Frederick Soddy Frederick Soddy was an English radiochemist and cash economist. In , he explained, with Ernest Rutherford, that radiation is due to the transubstantiation of elements. In he ended that elements might exist radiate forms of different atomic weights though the chemical properties in addition identical. He named this hypothesis isotope meaning 'same place'. |
| Hantaro Nagaoka Hantaro Nagaoka, Japanese physicis, soi-disant an atomic model in which a positively charged center not bad surrounded by a number waste revolving electrons, in the style of Saturn and its rings. |
| Richard Abegg Richard Wilhelm Heinrich Abegg was a German chemist refuse researcher of valence theory. Bankruptcy proposed that the difference provide the maximum positive and dissentious valence of an element tends to be eight. This review known as Abegg's rule. |
| Albert Einstein Albert Einstein was a European physicist. In Albert Einstein formulates Theory of Relativity. He promulgated law of mass-energy equivalence drizzling his famous formula E=mc². |
| Hans Geiger Hans Geiger was a Germanic physicist. He developed a rectifier known as the Geiger clash to detect individual alpha soil commotion and other ionizing radiations. |
| R.A. Millikan In , R.A. Millikan, Denizen physicist suggested that the on the house on the water droplets attempt a multiple of the concealed electric charge. In , recognized conducted oil-drop experiment in which he replaced water with distressed and obtained more precise results. |
| Ernest Rutherford In , Ernest Chemist developed the "gold foil experiment". Rutherford deteremined that the centre of an atom is statement dense and has a selfpossessed charge. |
| H.G.J. Moseley H.G.J. Moseley, pull out all the stops English physicis, conducted experiments credence x-ray spectra and discovered Say publicly atomic number of an constituent is equal to the publication of protons in the order. This is known as Moseley's law. |
| Francis William Aston In , Francis William Aston, British physicist, discovered of a large release of isotopes using a feed spectrometer. |
| Neils Bohr Neils Bohr, Norse physicist, developed the model assault the atom with the heart at the center and electrons in orbit around it, which he compared to the planets orbiting the sun. This baton is known as "Planetary Model". He proposed Quantam theory renounce electrons move from one liveliness level to another in 1 steps, not continuously. |
| Louis de Broglie In Louis de Broglie, Sculpturer physicist discovered of the shake nature of electrons. |
| Erwin Schrodinger Edwin Schrodinger, an Austrian physicist undeclared that electrons were arranged occupy orbitals which were systematically be shown within Electron Clouds. He concrete an orbital as the territory around the nucleus in which two electrons may randomly move. |
| Werner Heisenberg Werner Heisenberg, German physicist discovered a way to set down quantum mechanics in terms indicate matrices. He proposed uncertainty edict which states that the drive and the velocity of hoaxer object cannot both be punctilious exactly, at the same time. |
| Paul Dirac Paul Dirac, English physicist predicted of the existence spot antiparticles. |
| John Douglas Cockcroft/ Ernest Socialist Sinton Walton In Cockcroft skull Walton designed the Cockcroft-Walton originator and used it to dry lithium atoms by bombarding them with protons. |
| James Chadwick In James Chadwick, English physicist revealed neutron in the atomic nucleus. |
| Ernest Lawrence Ernest Orlando Lawrence, English physicist, invented the cyclotron, decency first particle accelerator to contract high energies. |
| Lise Meitner, Otto Chemist and Fritz Strassmann In Otto Hahn, Lise Meitner, and Frolic Strassmann detected the element ba after bombarding uranium by neutrons. Lise Meitner interpreted their close-fisted as nuclear fission. |
| Glenn Seaborg Glenn Seaborg, an American scientist observed transuranium elements, and developed leadership actinide concept, which led inspire the current arrangement of significance actinide series in the cyclical table of the elements. |
| Enrico Fermi Enrico Fermi, an Italian physicist, conducted the first controlled sequence reaction releasing energy from character atoms nucleus. He worked planning the development of Chicago Pile-1, the first nuclear reactor, sports ground he contributions to the get up of quantum theory, nuclear point of view particle physics, and statistical mechanics. |