I aquired a couple of glass tubes filled with a liquid metal, which, I suppose, can be used as switches.
The metal looks like mercury, but would they use such dangerous stuff? Or is it just some alloy?
Kanemsparkgap - 19-2-2005 at 03:05
Those tubes are most likely mercury switches. Mercury is the only (relatively) cheap metal that is liquid at ambient temperature. They're
supposedly safe since the mercury vapors are sealed in by the glass.
I don't know of any liquid amalgams/alloys of mercury.
sparky (^_^)tom haggen - 19-2-2005 at 12:01
Mercury is the only metal that is a liquid at room temperature.Darkfire - 19-2-2005 at 12:11
Quote:
Originally posted by tom haggen
Mercury is the only metal that is a liquid at room temperature.
Thats not true, its the only pure metal,
alloys of indium are liquid at room temp.JohnWW - 19-2-2005 at 14:21
And gallium also (or at least eutectic alloys of it with other low-melting metals), and the Na-K eutectic alloy.Reverend Necroticus Rex - 19-2-2005 at 14:36
Caesium metal is a liquid at just slightly above room temperature, held in a glass vial, it will melt in a warm hand.
Francium would probably be a liquid at room temperature, but for all purposes, francium doesn't exist.tom haggen - 19-2-2005 at 14:38
What other element is in the composition of this liquid indium alloy you speak of?
What do you mean francium doesn't exsist? It's a naturally occuring element.
[Edited on 19-2-2005 by tom haggen]
[Edited on 19-2-2005 by tom haggen]mick - 19-2-2005 at 16:23
I aquired a couple of glass tubes filled with a liquid metal, which, I suppose, can be used as switches.
The metal looks like mercury, but would they use such dangerous stuff? Or is it just some alloy?
If the glass tubes have metal connecters fused into the glass, they are mercury switches. I recently gave one of these away. Used to be used for
switches on 50s and top quality 60 and 70s cars for the light switch on the bonnet and boot.
If there are no connectors then it is a sealed glass vial of mercury. Should not be a problem unless you break it and do not clean the residue up
(sulfur works, mercury sulphide is very insoluble, leave it for at least 2 days or more). If you are doing chemistry with mercury be carefuful, if it
is soluble in water, inhaled or an organomercury compound it can be very poisonous.
The other thing I will be careful with is cadmium.
mick
A bit like lead, more poisonous to kids
[Edited on 20-2-2005 by mick]
[Edited on 20-2-2005 by mick]Reverend Necroticus Rex - 19-2-2005 at 17:26
Tom, I more meant to say that practically it may as well not exist, as the halflife is so short, and the radioactivity so high.
As there is only an ounce or less of Fr on the planet at any given time, and a mere few atoms created by man, it is just a lab curiosity, kind of like
astatine in that respect.neutrino - 19-2-2005 at 17:28
Quote:
Originally posted by tom haggen
What other element is in the composition of this liquid indium alloy you speak of?
What do you mean francium doesn't exsist? It's a naturally occuring element.
The alloy is 24% In, 76% Ga.
About francium… it’s not really natural. The most stable isotope has a half-life of 22 minutes, so anything that’s out there won’t last long.Mumbles - 20-2-2005 at 19:45
Quote:
Originally posted by Reverend Necroticus Rex
As there is only an ounce or less of Fr on the planet at any given time, and a mere few atoms created by man, it is just a lab curiosity, kind of like
astatine in that respect.
I thought it was less than a gram on earth at one time. Then again it is all speculation as you can't exactly go and weigh it out. Another
problem with francium is that it isn't a normal result from fission. From what I hear it is kind of a rare side reaction formed when Actnium
decays. It is on the order of 1 in every 100 fissions of actnium go to francium by alpha decay instead of the normal beta decay.tom haggen - 21-2-2005 at 10:24
That is very amazing how francium exsists on this planet. I never new that it was in such small abundance. I just saw that it was a naturally occuring
element on my periodic table, and thought nothing of it. I'm curious as to how the cycle of francium actual works so that its in such small
abundance. Once it's completely decayed, how does it not become an extinct element?
[Edited on 21-2-2005 by tom haggen]
[Edited on 21-2-2005 by tom haggen]The_Davster - 21-2-2005 at 10:57
Quote:
Originally posted by tom haggen
Once it's completely decayed, how does it not become an extinct element?
Because, as Mumbles mentioned, actinium is constantly decaying to form more francium.JohnWW - 21-2-2005 at 12:37
And protoactinium-231 is constantly decaying by alpha-emission to to form more actinium-227 (which decays mostly to francium-223 by alpha-emission). I
think this in turn comes from the much longer-lived uranium-235, the isotope of mprtance in "enriched uranium", although nearly all of
Earth's initial supply of this has decayed away.unionised - 22-2-2005 at 11:17
I know that gallium wets glass so you would have to use something else (polypropylene?) for a gallium filled "mercury" switch.
Does the same problem happen with indium alloys?
(BTW, isn't it a long time since someone mentioned mercury?)mick - 22-2-2005 at 12:02
With the melting points so close to "room temp" (depends where you live, we have got a bit of snow here and it feels cold to me) to use
anything except mercury for a switch would freeze and not be a switch. Mercury freezes at about -39 C.
mick
