Why, at room temp & pressure, is the dense metal mercury a liquid? It sort of goes against the grain. Are there any other elements liquid at room temp & pressure?
2007-08-04 09:42:03 · 10 answers · asked by Michael K 1 in Science & Mathematics ➔ Physics
Mercury's valence (i.e. outer most) electrons are 2 electrons in the 6s "shell." Because there are a pair, and the "shell" is full, mercury atoms don't share electrons very well. This means that mercury atoms don't bond to one another as well as other metals do.
2007-08-04 11:12:48 · answer #1 · answered by Thomas M 6 · 0⤊ 0⤋
Don't think the 6s pair tells the full story- this only explains the difference between adjacent elements in the periodic table, Gold and Thallium. Gallium, Francium and Bromine do not share this paired s electron property. Work out the 'binding energy' between mercury atoms, knowing the atomic radius and take into account the mutual shielding of the electron clouds on each nucleus. You get a 'ball park' figure of about 0.8eV an order of magnitude less than most atoms that size, including the metals. Now the ave particle energy at 300K is about 0.025eV. I suggest this is sufficient to disrupt any lattice structure. (much smaller than that and it would be a gas!) .Yes I know that the thermal energy<< than the BE, but it is sufficient to allow quantum tunnelling for the Hg atoms to escape the rigid lattice structure.Anyone tried to solidify Hg at room temp using pressure btw?!
2007-08-04 20:48:45 · answer #2 · answered by RTF 3 · 0⤊ 0⤋
The interatomic bond are too weak to lock them into position relative to each other. That's what a solid it. The bonds are only strong enough keep the atoms all together in a condensed form, though. That's why it's a liquid vs. a gas. Gallium is a liquid just above room temperature - about 85 or 90 F or there abouts. If you alloy it with about 5% indium (which has a much higher melting point), the melting point drops below room temperature for some reason.
2007-08-04 18:26:38 · answer #3 · answered by Dr. R 7 · 0⤊ 0⤋
Mercury is very soft and has a pretty high surface tension, which means the cohesive forces between atoms must be reasonably strong. The electrons are squeezed away by the core hogging so much space. The only other element that is liquid at room temp. is Bromine.
2007-08-04 16:54:07 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Materials are solids when the atoms or molecules within them bind together in a lattice. Mercury atoms, while bound together strongly by intermolecular forces - meaning it is dense - are not bound in a lattice at room temperature.
Basically it's all to do with different types of intermolecular forces.
The other liquid elements are caesium, francium, and gallium, and bromine.
2007-08-04 17:33:51 · answer #5 · answered by kangaruth 3 · 0⤊ 0⤋
Most solids have a high melting temperature.
For some reason of Inter-atomic attraction, Mercury melts at about -39°C and always has done. It's called an 'Anomaly'.
2007-08-04 18:40:31 · answer #6 · answered by Norrie 7 · 0⤊ 0⤋
Room temp is only important because that is basicaly the temp we live in. Forget that, and everything simplifies. All elements (as you know) can exist in different forms. In different temps.
2007-08-04 20:25:56 · answer #7 · answered by R.E.M.E. 5 · 0⤊ 0⤋
Well, just because it's a metal does not mean it has to be a solid. There are factors that qualify a certain element to be a metal; being solid is NOT one of them.
2007-08-04 17:10:23 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Because its melting point is below room temperature.
2007-08-05 15:10:54 · answer #9 · answered by Anonymous · 0⤊ 0⤋
The element mercury is as it is. Sorry if you don't like the way it is, but that is the way it is like it or not.
(You might also ask why is water wet, ice cold, the sun bright, why is the property of gravity such that it attracts. That is just the way things are.)
2007-08-04 16:48:35 · answer #10 · answered by Big Bill 7 · 0⤊ 5⤋