Question

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?

Answer 1

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.

• `(M/V_1)/(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 " fm"`

• radius of any atom: `1 " Å"`

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