Argument
Atomic nucleus
Overview
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford at the University of Manchester based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron in 1932, models for a nucleus composed of protons and neutrons were quickly developed by Dmitri Ivanenko and Werner Heisenberg. An atom is composed of a positively charged nucleus, with a cloud of negatively charged electrons surrounding it, bound together by electrostatic force. Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud. Protons and neutrons are bound together to form a nucleus by the nuclear force.
The diameter of the nucleus is in the range of 1.70 fm (1.70×10−15 m) for hydrogen (the diameter of a single proton) to about 11.7 fm for uranium. These dimensions are much smaller than the diameter of the atom itself (nucleus + electron cloud), by a factor of about 27,000 (uranium's atomic radius is about 156 pm (156×10−12 m)) to about 60,000 (hydrogen's atomic radius is about 52.92 pm).
The branch of physics involved with the study and understanding of the atomic nucleus, including its composition and the forces that bind it together, is called nuclear physics.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
Possible passages
Found by search and not yet checked by a person; they may only mention the idea in passing.
Another striking instance is afforded by Dalton’s generalization, commonly known as the atomic theory. It had been known from the very commencement of accurate chemical observation, that any two bodies combine chemically with one another in only a certain number of proportions; but those proportions were in each case…
John Stuart Mill, A System of Logic, Ratiocinative and Inductive
States what Atomic nucleus is.
Concerning the protoplasm contained in each cell, named by some cytoplasm, it remains to say that it always includes a small body called the centrosome, which appears to have a directive function. Usually the centrosome lies outside the nucleus, but is alleged to be sometimes within it. During what is called the "resting stage," or what might more properly be called the growing stage (for clearly the occasional…
Herbert Spencer, The Principles of Biology, Volume 1
States what Atomic nucleus is.
The theory that matter consists of “atoms”, _i.e._ of little bits that cannot be divided, is due to the Greeks, but with them it was only a speculation. The evidence for what is called the atomic theory was derived from chemistry, and the theory itself, in its nineteenth-century form, was mainly due to Dalton. It was found that there were a number of “elements”, and that other substances were compounds of these…
Bertrand Russell, Philosophy
States what Atomic nucleus is.
Philosophers who discussed Atomic nucleus
Related ideas
- Mass
- Particle physics
- Quark
- Quantum mechanics
- Werner Heisenberg
- Nature (journal)
- Standard Model
- Rutgers University
- Atom
- Electron
- Atomic physics
Place in the tradition
Part of Deductive-nomological model.