Gold vs. Iron

Most recent answer: 10/22/2007

Q:
Why gold is heavier than iron. or why the density of gold is more
- sridatri dutta (age 14)
ICSE Board class IX, TN , India
A:
Gold has many more protons and neutrons in the nucleus of each atom than iron does. So each gold atom weighs almost four times as much as each iron atom. The extra electrons in the gold atoms do make the atom a little bigger than an iron atom, but not a whole lot. So there are nearly as many gold atoms as iron atoms per volume, but each gold atom weighs a lot more. So gold ends up denser.

There’s a general trend that the volumes of the heavy atoms don’t go up as fast as the weights do, so they tend to form denser materials. If you’re interested in further explanation of that trend, let us know.

Mike

(published on 10/22/2007)