: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with the neutron is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673 × 10−27 kilogram
Examples of proton in a Sentence
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In the case of a passing lead atom, the loss of three protons through this process results in the formation of gold.
—
Victoria Corless, Space.com, 13 May 2025
However, a more common result is a process called electromagnetic dissociation which can see a small number of protons stripped off a lead ion with the removal of three protons effectively turning lead with its 82 protons into gold with its 79.
—Tim Treadgold, Forbes.com, 13 May 2025
And a new analysis of protons trapped in the inner radiation belt that surrounds Earth suggests a new Gleissberg cycle may be beginning.
—Meghan Bartels, Scientific American, 9 May 2025
Elements are determined by their number of protons.
—Margherita Bassi, Smithsonian Magazine, 7 May 2025
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Victoria Corless, Space.com, 13 May 2025
However, a more common result is a process called electromagnetic dissociation which can see a small number of protons stripped off a lead ion with the removal of three protons effectively turning lead with its 82 protons into gold with its 79.
—Tim Treadgold, Forbes.com, 13 May 2025
And a new analysis of protons trapped in the inner radiation belt that surrounds Earth suggests a new Gleissberg cycle may be beginning.
—Meghan Bartels, Scientific American, 9 May 2025
Elements are determined by their number of protons.
—Margherita Bassi, Smithsonian Magazine, 7 May 2025
See All Example Sentences for proton
Cite this Entry
“Proton.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/proton. Accessed 20 May. 2025.
Copy CitationKids Definition
proton
noun
pro·ton
ˈprō-ˌtän 
: an atomic particle that occurs in the nucleus of every atom and carries a positive charge equal in size to the negative charge of an electron
Medical Definition
proton
noun
pro·ton
ˈprō-ˌtän
: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with neutrons is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673×10−24 gram
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