nucleus, in physics: Size and Density

Size and Density

The nucleus occupies only a tiny fraction of the volume of an atom (the radius of the nucleus being some 10,000 to 100,000 times smaller than the radius of the atom as a whole), but it contains almost all the mass. An idea of the extreme density of the nucleus is revealed by a simple calculation. The radius of the nucleus of hydrogen is on the order of 10−13 cm so that its volume is on the order of 10−39 cm3 (cubic centimeter); its mass is about 10−24 g (gram). Combining these to estimate the density, we have 10−24 g/10−39 cm3 ≈ 1015 g/cm3, or about a thousand trillion times the density of matter at ordinary scales (the density of water is 1 g/cm3).

Sections in this article:

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.

See more Encyclopedia articles on: Physics