I watched Nova on PBS this week. The show was called Hunting the Elements and very interesting.
Initially they discussed gold. It's atomic weight is 197 (protons + neutrons) it's atomic number is 79 (protons). They said only 4 elements are denser than gold - rhenium 186 and 75, osmium 190 and 76, iridium 192 and 77 and finally platinum 195 and 78.
How can these 4 be denser than gold when their atomic weight is less than gold's?
There are many elements with atomic weights above gold's, aren't they denser if a solid vs a gas?
I wonder if this comment was a mistake? Nova is a pretty good show and I would be surprised if they made a blunder like that. Anyone here know?
Here's and excellent periodic table - Dynamic Periodic Table