Find the mass of one atom by:
8.33 x 10^{-16} / 2.5 x 10^{6} = 3.32 x 10^{-22} g
Convert it into amu.
1 g = 6.022 x 10^{23} amu
so, 3.32 x 10^{-22} x 6.022 x 10^{23} = 200.6 amu
Now look at the periodic table and search for 200.6 amu element.
The element is Mercury (Hg)
