# Show that the nuclear density of 1H1(mass no-1&atomic no-1)is over 10^14 times greater than its atomic density (assume the atom to have the radius of the first Bohr orbit).In this question,what should I put for nuclear mass&atomic mass?

May 20, 2018

see below

#### Explanation:

You don't need a number for mass. You are comparing densities, and the related mass, $M$, is the same in each case, ie the proton.

• $\frac{\frac{M}{V} _ 1}{\frac{M}{V} _ 2} = {V}_{2} / {V}_{1}$

So you are really comparing the (spherical) volumes of the H nucleus and the H first orbital.

Common approximation:

• radius of any nucleus: $1 \text{ fm}$

• radius of any atom: $1 \text{ Å}$

Google for the actual dimensions if you want to be more precise :)