From:  Hooligan
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On: 2008/11/03 09:52:31
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From http://www.simetric.co.uk/si_water.htm
'Water is the only substance on Earth that exists in all three physical states of matter: solid, liquid and gas.'
how about mercury? It's a liquid obviously, it can freeze in the bulb if it's too cold and it's danger comes from mercury vapour emitted by the liquid.
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From: sanstete
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On: 2008/11/03 09:59:53
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I think the key is "does" rather than "can" and also I think they mean under natural conditions.
The temperatures to freeze and boil mercury probably exist on earth but mercury is not naturally found in these places.
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From: Hooligan
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On: 2008/11/03 10:09:31
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I think solid methane exists at the bottom of the sea, dunno about liquid though
so there probably `isn't any naturally occurring liquid mercury.
What about volcanoes? Can you get liquid sulfur? can't remember
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From: Hooligan
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On: 2008/11/03 10:11:43
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wikipedia lists sulfur as having a melting and boiling point that are quite different, so you must surely sometimes get liquid and gaseous sulfur in a volcano.
Yes I've debunked quasi scientific bunk written by amateurs, they needed proof before making this cool sounding but baseless claim. I was designed for better things, but fate intervened of course.
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From: stone5150
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On: 2008/11/03 10:38:43
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They left out a word is all.
'Water is the only substance on Earth that commonly exists in all three physical states of matter: solid, liquid and gas.'
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From: PaulHews
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On: 2008/11/03 11:46:34
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Also duck quacks do echo!
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From: rid
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On: 2008/11/03 13:01:02
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Water has a "triple point" at 0°C, where it DOES exist as vapour, liquid and solid. That may be what is discussed. Not many elements or compounds have triple points AFAIK.
/RID
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From: PaulHews
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On: 2008/11/03 13:08:14
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>Not many elements or compounds have triple points AFAIK.
I thought they all have triple points? (That might have been a day in chem class when I was asleep.)
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From: rid
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On: 2008/11/03 13:15:24
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I admit to sleeping as well, if that is what it takes to misunderstand. However, I seem to remember a discussion about water as being somewhat unique in having a triple point, but I admit that may have been qualified by some info that I have forgotten. Possibly it was about happening in a humanly understandable temperature or pressure range (like 0°C and normal atmospheric pressure) or something like that. I guess you'll find triple points for mercury and iron as well, but those will sort of happen in a fairly hostile environment (like at -40°C or at + 1000°C). I suppose you have found me to err and I plead mercy.
/RID
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From: stevenb
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On: 2008/11/03 19:03:46
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I doubt that gaseous elemental sulphur (or liquid for that matter) exists under natural conditions on Earth. Solid elemental sulphur is found in volcanic regions, but I would guess that in these environments any heating would result in various sulphide and sulphate compounds rather than gaseous suphur in anything other than the most trivially minute trace quantities.
I can't think of any other compound or element, other than water, that exists in all three states on Earth. It seems like a reasonable assertion to me.
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From: PaulHews
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On: 2008/11/03 20:56:36
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The most likely suspects are substances that are liquid at room temp, because there's always some transference to gaseous form, and it can always get colder. Mercury is the most obvious elemental choice, as Hooligan pointed out at the start.
Off the top of my head, there's all kinds of hydrocarbons that vaporise at relatively low temperatures, and can freeze as well.
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From: Hooligan
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On: 2008/11/04 03:38:02
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Lead is another contender, it could easily melt in a volcano, from various ores.
Mercury apparently sometimes exists as a native metal, according to wikipedia.
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From: stevenb
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On: 2008/11/04 03:50:13
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There are plenty of elements and compounds that could exist in all three states on Earth, but I think the point is that they don't occur naturally. Bromine is probably the best example that I can think of.
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From: sanstete
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On: 2008/11/04 04:00:24
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Yeah. I think I said that.
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From: stevenb
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On: 2008/11/04 04:02:26
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Indeed you did, excuse me.
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From: sanstete
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On: 2008/11/04 04:07:18
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:-)
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From: Hooligan
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On: 2008/11/04 04:45:19
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that's the point, I'm trying to think of substances that can be found under non-man made conditions - so mercury in the centre of a freezing rock at antartica, permanently frozen solid, has appeared naturally.
A river of lead flowing from a volcano has appeared naturally, if that can happen.
methane apparently combines with water at high pressure to form a solid on the bed of the ocean, so it's not really solid methane as such, and I'm not sure if there's any natural occurring liquid methane
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From: Pino Carafa
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On: 2008/11/04 07:40:54
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Interesting
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From: higginspi
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On: 2008/11/07 12:31:05
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Shit commonly exists as solid, liquid, and gas.
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From: stone5150
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On: 2008/11/07 14:10:50
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Ask your doctor about Pepto and Gas-X.
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From: Hooligan
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On: 2008/11/08 05:50:27
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higginspi - ingenious bit of lateral thinking there.
I guess it's the old FerroCeriumMonoSulphide compound, chemical formula FeCeS
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From: stone5150
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On: 2008/11/08 10:44:35
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Ohh, it has sulfur in it? No wonder it stinks.
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