Originally posted by najdorfslayer
Most book say that mercury is a liquid due to the "inert pair" effect. This is a cop out!
The reason is to do with 'reletivistic contraction'.
Can a physist explain this so a simple chemist can underdstand it!!
I had absolutely no idea why myself so I googled it and got this:
….Mercury hangs on to its valence 6s electrons very tightly. Mercury-mercury bonding is very weak because its valence electrons are not shared readily. ….
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.
The link also gives more relevant info on this.
I never realised that relativity can explain the physical properties of an element so explicitly! -this at least appears to be yet another peace of strong evidence to vindicate relativity.
I also found this link:
I hope this helps.