Ad
related to: atomic theory development timeline definition biology dictionary worksheet
Search results
Results From The WOW.Com Content Network
Atomic theory is the scientific theory that matter is composed of particles called atoms. The definition of the word "atom" has changed over the years in response to scientific discoveries. The definition of the word "atom" has changed over the years in response to scientific discoveries.
This timeline lists significant discoveries in physics and the laws of nature, including experimental discoveries, theoretical proposals that were confirmed experimentally, and theories that have significantly influenced current thinking in modern physics. Such discoveries are often a multi-step, multi-person process.
1924 Satyendra Bose and Albert Einstein introduce Bose–Einstein statistics. 1925 George Uhlenbeck and Samuel Goudsmit postulate electron spin. 1925 Pierre Auger discovers the Auger process (2 years after Lise Meitner) 1925 Werner Heisenberg, Max Born, and Pascual Jordan formulate quantum matrix mechanics.
Electrons and a compact nucleus of protons and neutrons. Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms.
The Bohr–Sommerfeld model (also known as the Sommerfeld model or Bohr–Sommerfeld theory) was an extension of the Bohr model to allow elliptical orbits of electrons around an atomic nucleus. Bohr–Sommerfeld theory is named after Danish physicist Niels Bohr and German physicist Arnold Sommerfeld. Sommerfeld showed that, if electronic orbits ...
The Bohr model is a relatively primitive model of the hydrogen atom, compared to the valence shell model. As a theory, it can be derived as a first-order approximation of the hydrogen atom using the broader and much more accurate quantum mechanics and thus may be considered to be an obsolete scientific theory.
The plum pudding model was the first scientific model of the atom to describe an internal structure. It was first proposed by J. J. Thomson in 1904 following his discovery of the electron in 1897, and was rendered obsolete by Ernest Rutherford 's discovery of the atomic nucleus in 1911. The model tried to account for two properties of atoms ...
1774 – Charles Mason: Conducts an experiment near the Scottish mountain of Schiehallion that attempts to measure the mean density of the Earth for the first time. Known as the Schiehallion experiment. 1796 – Edward Jenner: tests the first vaccine. 1798 – Henry Cavendish: Torsion bar experiment to measure Newton's gravitational constant.