| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,771,536,826 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
atomic nucleus |
Also found in: Wikipedia | 0.02 sec. |
|
atomic nucleus [ə′täm·ik ′nü·klē·əs] (astronomy) Atomic nucleus The central region of an atom. Atoms are composed of negatively charged electrons, positively charged protons, and electrically neutral neutrons. The protons and neutrons (collectively known as nucleons) are located in a small central region known as the nucleus. The electrons move in orbits which are large in comparison with the dimensions of the nucleus itself. Protons and neutrons possess approximately equal masses, each roughly 1840 times that of an electron. The number of nucleons in a nucleus is given by the mass number A and the number of protons by the atomic number Z. Nuclear radii r are given approximately by r = 1.2 × 10-15 m A1/3. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in | ? References in periodicals archive | ||
|---|---|---|---|
| 7 billion years ago, all matter was smaller than the nucleus of an atom. A biography needs a theme around which facts are placed like electrons around the nucleus of an atom. In the same way that certain elementary particles -- protons and neutrons -- make up the nucleus of an atom, a group of elementary snowballs may form a comet. |
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|