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I believe there are 15 747 724 136 275 002 577 605 653 961 181 555 468 044 717 914 527 116 709 366 231 425 076 185 631 031 296 protons in the universe and the same number of electrons. [5] This large number was soon named the "Eddington number".
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).
An atom consists of a small, heavy nucleus surrounded by a relatively large, light cloud of electrons. An atomic nucleus consists of 1 or more protons and 0 or more neutrons. Protons and neutrons are, in turn, made of quarks. Each type of atom corresponds to a specific chemical element. To date, 118 elements have been discovered or created.
There are two types of quarks in atoms, each having a fractional electric charge. Protons are composed of two up quarks (each with charge + 2 / 3 ) and one down quark (with a charge of − 1 / 3 ). Neutrons consist of one up quark and two down quarks. This distinction accounts for the difference in mass and charge between the two ...
Since protons and neutrons have approximately the same mass (and the mass of the electrons is negligible for many purposes) and the mass defect of the nucleon binding is always small compared to the nucleon mass, the atomic mass of any atom, when expressed in daltons (making a quantity called the "relative isotopic mass"), is within 1% of the ...
Depiction of a hydrogen atom showing the diameter as about twice the Bohr model radius. (Image not to scale) A hydrogen atom is an atom of the chemical element hydrogen.The electrically neutral hydrogen atom contains a single positively charged proton in the nucleus, and a single negatively charged electron bound to the nucleus by the Coulomb force.
Helium-3 (3 He [1] [2] see also helion) is a light, stable isotope of helium with two protons and one neutron. (In contrast, the most common isotope, helium-4, has two protons and two neutrons.) Helium-3 and protium (ordinary hydrogen) are the only stable nuclides with more protons than neutrons. It was discovered in 1939.
protons and neutrons have different masses, [7] [8] and different nuclides have different ratios of protons and neutrons. atomic masses are reduced, to different extents, by their binding energies. The ratio of atomic mass to mass number (number of nucleons) varies from 0.998 838 1346 (51) for 56 Fe to 1.007 825 031 898 (14) for 1 H.