I know what you've been wondering...

...and I've been wondering the same thing. Why the heck is Mercury a liquid??? None of the other heavy metals are! Well, wonder no more! It's actually pretty cool. I'm not sure how familiar you are with molecular orbitals and valence bonding theory, so let me try to explain without them. Basically, every atom has certain layers of electrons, kinda like the planets orbiting around the sun; only instead of having one planet in each orbit, you can put either 2, 6, 10, or 14 electrons in a certain orbit. If that orbit happens to not be full, then any electrons in the unfilled orbit can be used to bond with another atom and make a molecule. The other heavy metals use this very principle to link together into solids. Well, it just so happens that mercury is the perfect size and shape that special relativity takes an effect on the electrons it would normally use to bond and they are moving soooo fast that due to Einstein's famous equation they gain mass because they are moving at a large fraction of the speed of light. Because they gain mass, they move closer to the nucleus of the atom, and in turn, are hidden under the filled orbitals of the atom, and thus are unable to bond. So mercury remains a liquid with the metallic luster of all the metals we see every day!

Okay, okay! I'll get a life some day and find something interesting to post on here. Until then, enjoy!