Unless you are a hobbyist or technician who solders things on a regular basis, your only acquaintance with the metallic element bismuth is probably through Pepto Bismol, the main ingredient of which is bismuth subsalicylate, a pinkish substance sold, not surprisingly, under the name of pink bismuth. The fact that you can ingest pink bismuth and it will soothe your stomach should tell you something about its toxicity; it's quite low. And, that's why bismuth is favored over lead for soldering. It is now widely used for soldering of circuit…