noun Physics, Astronomy.
a series of thermonuclear reactions, responsible for the energy production in stars like the sun, in which the nuclei of hydrogen atoms are transformed into helium nuclei by sequential addition of single hydrogen nuclei.
Why is a new element named after a suburb of San Francisco?On Saturday the International Union of Pure and Applied Chemistry proposed the names of two new elements. Currently element number 114 and element number 116 do not have official names in the periodic table of elements. The elements were previously known as ununquadium and ununhexium. Those long, unpronounceable words were the temporarily used systematic element names. The names are generated from their atomic number, but …
OTFRead more in this article about some frequently asked questions and fun facts related to our definitions.
- proton microscope,
- proton number,
- proton synchrotron,
- proton-pump inhibitor,
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
A set of thermonuclear reactions in which hydrogen nuclei (protons) fuse to form deuterium; these then fuse to form light helium isotopes, releasing more hydrogen nuclei that undergo further fusion with each other and with other nuclei. The main product of the proton-proton chain is He 4, the most common isotope of helium. The proton-proton chain releases large amounts of energy and involves the conversion of protons into neutrons, positrons, and electron neutrinos. The proton-proton chain is the main reaction in most main-sequence stars, including the Sun. See also carbon cycle triple alpha process.
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