求分子密度表

The table quoted in the above post only gives the density of an element (mass per unit volume), NOT the 'density' of atoms (in terms of the number of atoms per unit volume) in an element.

However, the atomic density can be worked out from the mass density.
Using Avogadro's hytpothesis, 1 mole of an element contains 6 x 10^23 atoms.
Let M be the molecular mass of an element in grams, thus M grams of an element contains 6x10^23 atoms, or mass of an atom = M/6x10^23 gram

Since density d = mass/volume, thus volume of an atom = mass/d
i.e. volume of an atom = M/(6x10^23 d) cm^3

Hence, atomic density = 6x10^23( d/M) atoms/cm3

For gold, d = 19.32 g/cm3, M = 197 g
hence, atomic density = 5.9 x 10 ^22 atoms/cm3

For platinum, d = 21.45 g/cm3, M= 195 g
hence, atomic density = 6.6 x 10^22 atoms/cm3

For Osmium, d = 22.6 g/cm3, M = 190 g
hence, atomic density = 7.1 x 10^22 atoms/cm3

Therefore, glod is, in fact, NOT the element with the highest atomic density.

http://www.science.co.il/PTelements.asp?s=Density