Chapter 17, Problem 17A

To determine

To explain: The comparison of mass of an atomic nucleus with the mass of the whole atom.

Explanation of Solution

Introduction:

The atom consists of a nucleus that is positively charged and a negatively charged electrons revolvesaround the nucleus in a regular orbits.

Protons and neutrons together forms the nucleus of an atom. The number of electrons present in an atom is exactly equal to the number of protons in that atom. The mass of proton and that of neutron are approximately equal and the mass of an electron is approximately equal to $\frac{1}{1836}$ times to that of proton. That means total mass of electrons in an atom is roughly equal to $\frac{1}{2\times 1836}$ times that of nucleus of that atom. This value is very small. Hence the entire mass of an atom is considered to be concentrated in its nucleus.