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?
You don't need a number for mass. You are comparing densities, and the related mass,
#(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.
radius of any nucleus:
#1 " fm"#
radius of any atom:
#1 " Å"#
Google for the actual dimensions if you want to be more precise :)