The answer is steel because you cannot pick water, oxygen, or gold out of a mixture.
density= mass/volume
we need the volume of the metal to find the density, in which case the answer would be 64.2/volume=density
This is a bit long right now.
(n l m s) these are the numbers.
n=2, second orbital level.
l is the type of orbit: l=1 elongated, l=0 spherical
m=0, magnetic number: 0
s=spin, both have spin positive
You need still to round it up. Srry!