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A proton is a stable subatomic particle, symbol p, H +, or 1 H + with a positive electric charge of +1 e (elementary charge).Its mass is slightly less than the mass of a neutron and approximately 1836 times the mass of an electron (the proton-to-electron mass ratio).
tau mass 3.167 54 (21) × 10 −27 kg: 6.8 × 10 −5 [29] proton mass 1.672 621 925 95 (52) × 10 −27 kg: 3.1 × 10 −10 [30] neutron mass 1.674 927 500 56 (85) × 10 −27 kg: 5.1 × 10 −10 [31] / proton-to-electron mass ratio: 1 836.152 673 426 (32) 1.7 × 10 −11 [32]
Alternately, the atomic mass of a carbon-12 atom may be expressed in any other mass units: for example, the atomic mass of a carbon-12 atom is 1.992 646 882 70 (62) × 10 −26 kg. As is the case for the related atomic mass when expressed in daltons , the relative isotopic mass numbers of nuclides other than carbon-12 are not whole numbers, but ...
Protons have a positive charge and a mass of 1.6726 × 10 −27 kg. The number of protons in an atom is called its atomic number. Ernest Rutherford (1919) observed that nitrogen under alpha-particle bombardment ejects what appeared to be hydrogen nuclei.
One dalton is approximately the mass of one a single proton or neutron. [2] The unified atomic mass unit has a value of 1.660 538 921 (73) × 10 −27 kg. [3] The amu without the "unified" prefix is an obsolete unit based on oxygen, which was replaced in 1961.
For example, the mass of an unbound atom of the common hydrogen isotope (hydrogen-1, protium) is 1.007 825 032 241 (94) Da, [a] the mass of a proton is 1.007 276 466 5789 (83) Da, [7] the mass of a free neutron is 1.008 664 916 06 (40) Da, [8] and the mass of a hydrogen-2 (deuterium) atom is 2.014 101 778 114 (122) Da. [9]
2.176 434 (24) × 10 −8 kg ... the strength of gravity simply is what it is, a primary quantity, while the proton's mass is the tiny number 1/13 quintillion.
The masses of the proton and neutron are similar: for the proton it is 1.6726 × 10 −27 kg (938.27 MeV/c 2), while for the neutron it is 1.6749 × 10 −27 kg (939.57 MeV/c 2); the neutron is roughly 0.13% heavier. The similarity in mass can be explained roughly by the slight difference in masses of up quarks and down quarks composing the ...