An example of the sort of trivial-but-instructive sort of things I do on an everyday basis is below. This one is from about an hour ago.
I got a sample of 2 g of barium as several chunks in a little vial filled with mineral oil. I just tried adding little chunks of it to methanol (99.8%) and isopropanol (99.9%) on my nightstand. Surprisingly the reaction of a 400 mg chunk with 10 mL methanol was almost as vigorous as it is with water, rapidly bubbling off hydrogen and heating the tube above 40 C. It dissolved completely and now I have barium methoxide. I figured it would react, but I thought it would be much slower and saturate far sooner. If anyone wants a
superbase, not only stronger than the hydroxide ion itself but also containing a toxic heavy metal, I'm your man.
As expected, the isopropanol reaction with 70 mg wasn't anywhere near as strong, but it still gave off some decent bubbles until saturating about halfway through the chunk and leaving a chalky white suspension with a little chunk of barium metal on the bottom. I tried adding a little bit of sodium bisulfate (an acid salt) to it to raise the acidity, but then I realized that this was exactly the wrong thing to add - it just made more white powder in the form of barium sulfate, which is totally insoluble in anything.
Also, I added one piece of barium to the large pile of stuff next to my bed, and a bunch of mineral oil to the right half of the nightstand and the floor all around it. Just like me, leaving a chunk of a highly reactive and somewhat toxic metal lying around in a giant pile of gadgets and garbage in equal proportion. If only it were radioactive, I'd be able to find it with my Geiger counter. But it's not, sadly. At least it's less than 1/10 what would be needed to kill me even if I somehow ate it.
I do occasionally taste chemicals though, as long as I know I'm orders of magnitude away from a toxic dose. E.g. I did once taste a few drops of copper sulfate solution, and what stuck out to me is that it tasted a combination of bitter and metallic. I've long suspected that there are considerably more than five fundamental tastes, and "metallic" seems to be one of them. Wikipedia has a little bit of speculation that galvanic currents in the mouth might trigger some receptor response that's responsible for this.
So now I just thought of something else to try. I might try putting a copper strip in my mouth, then a zinc strip, and then both together at the same time on opposite sides of my tongue - the classic galvanic cell, with my tongue itself acting as the salt bridge. If galvanic reactions are responsible, both together will taste far more metallic than either alone. If not, there's something else going on; some transition metal ions might just trigger taste receptor(s) of their own.
Oh, and just so everyone knows: lithium, potassium, rubidium, and ammonium chlorides all do have a little bit of saltiness to them, but not much; bitter and sour sensations come up too and are usually stronger than the salty flavor. Our salt receptors are really looking only for sodium ions; similar +1 cations trigger them only weakly.
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(edit: Second mini-experiment, done after the first post)
Screw copper and zinc. I just tried some bits of silver shot and magnesium ribbon. That's about as far apart as you can get in the galvanic series, without getting into stuff that's too expensive and unreactive (gold, platinum, etc) or that would react vigorously with my saliva, burning my tongue both by temperature, by extreme alkalinity, and in some cases even exploding (all alkali metals, plus all alkaline earths from calcium down to barium).
Both tasted fairly metallic on their own, but the combination of the two didn't seem to affect much on an under/over tongue basis. However, when the magnesium ribbon was placed on the top tip of my tongue with the silver also on the top but in the middle, the metallic flavor shot up, concurrent with feeling some electric sensation. This increased further as the magnesium was brought closer to the silver.
I think this lends some support to the galvanic hypothesis, with an added comment that the tongue doesn't seem to care as much about currents through it from bottom to top as currents across the top. The electro-metallic receptors are seemingly concentrated on the top.
I was still skeptical, so I just now tried two other things. First, tasting a Canadian nickel from back when Valka was young and Canada was making nickels out of pure nickel. There was a little metallic flavor there, but much less. Nickel in bulk form is closer to the middle of the series although closer to the copper end. And now I'm rolling around an ounce of tin (middle of series) in my mouth. Virtually no metallic flavor at all, and I gave it a good couple of minutes. So yeah, now I'm quite convinced we're mostly tasting galvanic currents when we taste metals.
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Comments and borderline-rant about why this sort of thing is important
What you see here is the value of experiential amateur "science", or if you prefer just playing with things until you've learned something about the world. All you can get from just looking at the Wikipedia page on "metallic flavor" is a bunch of tentative hypotheses, one of which was very easily testable. Google Scholar might come up with something more definitive, but in general the details are hard to figure out and it would take much longer to figure out what was going on.
Meanwhile it was totally simple to test out the given Wikipedia hypothesis, armed with a few bits of several kinds of metal and some chemistry knowledge about galvanic cells, and what I can safely put in my mouth, and whatnot.
Sometimes you can find things out on your own just by playing with stuff. I like my Wikipedia and Google Scholar voyages, but I also learn like two or three things a day just by making up little experiments and trying things out.
Screw paranoia about safety when you're many orders of magnitude from danger. Science paranoia has killed many people's interests in science altogether, and shunted more into fields of science where you have to look at a computer screen all day. If we want real STEM education, we need to stop overplaying risks.
Yes, don't make high explosives or drugs, and treat caustic and/or toxic chemicals with respect, and do wear gloves and goggles whenever needed, and beware of chemical incompatibilities. But we should stop creating a world where nobody tries to figure science things out on their own, preferring instead to just memorize them for the exam and then purge them from memory immediately, or look them up on Wikipedia and then forget them because they haven't connected enough dots to know where the new knowledge fits.