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Nuclear chemistry. Alpha decay is one type of radioactive decay, in which an atomic nucleus emits an alpha particle, and thereby transforms (or "decays") into an atom with a mass number decreased by 4 and atomic number decreased by 2. Nuclear chemistry is the sub-field of chemistry dealing with radioactivity, nuclear processes, and ...
The prevailing model of atomic structure before Rutherford's experiments was devised by J. J. Thomson. [1]: 123 Thomson had discovered the electron through his work on cathode rays [2] and between 1897 and 1904 he developed a model for atoms containing electrons arranged in concentric shells.
Induced radioactivity, also called artificial radioactivity or man-made radioactivity, is the process of using radiation to make a previously stable material radioactive. [1] The husband-and-wife team of Irène Joliot-Curie and Frédéric Joliot-Curie discovered induced radioactivity in 1934, and they shared the 1935 Nobel Prize in Chemistry ...
Specific activity. Specific activity (symbol a) is the activity per unit mass of a radionuclide and is a physical property of that radionuclide. [1][2] It is usually given in units of becquerel per kilogram (Bq/kg), but another commonly used unit of specific activity is the curie per gram (Ci/g). In the context of radioactivity, activity or ...
[1] Radioactive decay is a random process at the level of single atoms. According to quantum theory, it is impossible to predict when a particular atom will decay, regardless of how long the atom has existed. [2] [3] [4] However, for a significant number of identical atoms, the overall decay rate can be expressed as a decay constant or as half ...
The discovery of the neutron and its properties was central to the extraordinary developments in atomic physics in the first half of the 20th century. Early in the century, Ernest Rutherford developed a crude model of the atom, [1]: 188 [2] based on the gold foil experiment of Hans Geiger and Ernest Marsden. In this model, atoms had their mass ...
Radium 226 source in a cloud chamber. A cloud chamber, also known as a Wilson chamber, is a particle detector used for visualizing the passage of ionizing radiation. A cloud chamber consists of a sealed environment containing a supersaturated vapor of water or alcohol. An energetic charged particle (for example, an alpha or beta particle ...
X-rays are electromagnetic waves with a wavelength less than about 10 −9 m (greater than 3 × 10 17 Hz and 1240 eV). A smaller wavelength corresponds to a higher energy according to the equation E = h c/λ. (E is Energy; h is the Planck constant; c is the speed of light; λ is wavelength.) When an X-ray photon collides with an atom, the atom ...