Hg

[Riogho]

This barely fits in this category, so forgive me.

 

I was wondering the other day in Chemistry why Hg (mercury) was a liquid at STP. I looked into it a little bit and found out that mercury was also the only metal that didn't form a diatomic molecule when in a gaseous state.

 

I read on it, and it said something about the valence electrons of mercury being in the 6s orbital, and the fact that it was so close to the nucleus that the electrons flew at really high speeds around the nucleus and relativity took effect and the mass of those electrons increased.

 

My question is, I thought that relativity couldn't work on such small scales as electrons and such? Or maybe I've just misunderstood it all.

 

Clarification?

[Gilded]

Relativity "works" always. Actually, effects of relativity are especially evident at small scales, particles' lifetimes affected by their extreme velocities and so forth.

[pioneer]

Most metals readily share their outer most or valence electrons thereby becoming solid at room temperature. This sharing is why why metals are good conductors of electricity. Mercury holds its valence electrons tightly, the result is mercury can't share enough valence electron density to be a solid at room temperature. Also mercury is a poorer conductor of electricity compared to metals.

 

Why is the pair of 6s electrons so inert? The s electrons are able to come very close to the nucleus. They swing around very massive nuclei at speeds comparable to that of light. When objects move at such high speeds, relativistic effects occur. The s electrons behave as though they were more massive than electrons moving at slower speeds. The increased mass causes them to spend more time close to the nucleus. This relativistic contraction of the 6s orbital lowers its energy and makes its electrons much less likely to participate in chemistry- they're buried deep in the atomic core.

 

http://antoine.frostburg.edu/chem/senese/101/periodic/faq/why-is-mercury-liquid.shtml

[Mr Skeptic]

I think it is general relativity, rather than special relativity, that might not work at small levels. This is because GR and quantum theories of gravity currently don't play nice together. Special relativity always works (given inertial frame), but it is easier to notice when objects move fast. This is particularly easy to do with small particles. In fact, I've never heard of larger objects moving at a speed large enough that classical physics can't handle with over 99% accuracy.

[Riogho]

Yep, Yep. I know what SR and GR is. But when ijust hear the word 'relativity' i tend to think GR. After thinking through it a little bit i realized my error.