“What’s the only metal that is liquid at room temperature?”
If you’ve spent enough time as a fan of trivia, you will probably have heard variations on this question a few dozen times. You can probably recite it your sleep:
Mercury. (Sorry, that’s the car.)
Mercury. (Dang! That’s the planet.)
Mercury. (AHHH! That’s the US Space Program!)
If you are a child of the 80’s you may even remember teachers letting you play with it in science class.
It turns out that this was not a good idea.
I mean seriously bad.
(Seriously, the 1980s had to be one of the most dangerous environments for kids. WTH Lawn Darts?)
If you don’t want to click through those links, some of the lovely effects mercury can have on you include:
- memory loss
- neuromuscular effects
- cognitive and motor dysfunction
- kidney toxicity
Obviously, this made it a great substance for kids, and of course we have packed it into thermometers, fluorescent lighting, dental fillings, and mascara. Fortunately, the US has been phasing out mercury in thermometers for some years now, and many countries have banned them altogether. There are also increasing restrictions on mercury in many industrial applications.
That’s great, but is mercury really the only metal that is a liquid? The only molten metal that’s cool enough to touch?
It’s true, mercury is the only metal that’s liquid at room temperature — if you have air conditioning.
If you keep the windows open, and enjoy a bit of heat, there is also GALLIUM.
Gallium melts at 29.76 °C. (That’s 85.6 °F in real units.) My grandmother keeps her house a few degrees warmer than that year round, so all her gallium would be free flowing liquid.
Even better, gallium is non-toxic, so you can play with it without worrying about destroying the environment or your brain. It even has some medical applications. There are a ton of cool gallium related videos on Youtube. Probably the coolest use of gallium is the “disappearing teaspoon” magic trick/prank.
So the next time you are asked about “the only metal that’s liquid at room temperature” make sure you ask how hot the room is.