Search results
Results from the WOW.Com Content Network
The Rutherford paper suggested that the central charge of an atom might be "proportional" to its atomic mass in hydrogen mass units u (roughly 1/2 of it, in Rutherford's model). For gold, this mass number is 197 (not then known to great accuracy) and was therefore modelled by Rutherford to be possibly 196 u.
Ernest Rutherford, 1st Baron Rutherford of Nelson (30 August 1871 – 19 October 1937) was a New Zealand physicist who was a pioneering researcher in both atomic and nuclear physics. He has been described as "the father of nuclear physics", [ 7 ] and "the greatest experimentalist since Michael Faraday ". [ 8 ]
The prevailing model of atomic structure before Rutherford's experiments was devised by J. J. Thomson. [2]: 123 Thomson had discovered the electron through his work on cathode rays [3] and proposed that they existed within atoms, and an electric current is electrons hopping from one atom to an adjacent one in a series.
Rutherford's model, being supported primarily by scattering data unfamiliar to many scientists, did not catch on until Niels Bohr joined Rutherford's lab and developed a new model for the electrons. [54]: 304 Rutherford model predicted that the scattering of alpha particles would be proportional to the square of the atomic charge.
A schematic of the nucleus of an atom indicating β − radiation, the emission of a fast electron from the nucleus (the accompanying antineutrino is omitted). In the Rutherford model for the nucleus, a red sphere was a proton with positive charge, and a blue sphere was a proton tightly bound to an electron, with no net charge.
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 then known: that there are electrons, and that atoms have no net electric charge.
1916 Gilbert N. Lewis and Irving Langmuir formulate an electron shell model of chemical bonding; 1917 Albert Einstein introduces the idea of stimulated radiation emission; 1918 Ernest Rutherford notices that, when alpha particles were shot into nitrogen gas, his scintillation detectors showed the signatures of hydrogen nuclei.
In atomic physics, the Bohr model or Rutherford–Bohr model was the first successful model of the atom. Developed from 1911 to 1918 by Niels Bohr and building on Ernest Rutherford 's nuclear model , it supplanted the plum pudding model of J J Thomson only to be replaced by the quantum atomic model in the 1920s.