Okay, I've got a piece of crystalline bismuth, so you can actually take sort of pellets of bismuth, metal, and heat it up, I've seen photos of people doing that on their home cookers, their ovens and things, but you can make them in the lab so you get crystals of bismuth out which look like this which is actually really really pretty and there are websites of people who've made these crystals and they're selling them for collectors and things which is quite nice. Bismuth is interesting because it is the heaviest element that is not radioactive. You can imagine the nucleus, the center of the atom, rather like a drop of water, and if you imagine a drop of water as it gets bigger and bigger it becomes unstable and will usually split into two, and it just happens that bismuth is the largest size that's not radioactive. - The interesting thing about bismuth actually is that it's long been regarded, bismuth 209 has long been regarded as the heaviest non-radioactive element, and technically actually that's not true. It was actually found I think about 5 years ago now, it was actually proven to be an alpha emitter, so it's actually a radioactive element, that emits alpha particles. - So here is a very old sample of bismuth. This is a bismuth rod and as you can see it's packed up really quite nicely, but if we open this then we can go in and see what it is in here. Let's see. Here if we pull it out carfully. - But actually it's kind of a little bit pedantic I suppose because the half life of this bismuth 209 they've found is actually 1.9x10 to the power of 19 years. Its half life, that's the time it takes a kilo of bismuth, for 500 grams of it to decompose to its daughter element which I think is thalium 205 if I'm right, and so that half life is actually longer than the current age of the universe, so for all intents and purposes, it's still quite stable and I think they actually call it meta stable. - It is used particularly in an alloy which they call woods metal, which is a very low melting alloy, will even melt in boiling water, and there are endless practical jokes where you can buy woods metal spoons and give it to somebody to stir their tea and it melted in their tea and they look suprised. - Bismuth. Really old sample from Johnson Matthey and let's see if we can find out what the purity is, so it's 99.9%, really a quite nice sample of a bismuth rod. - Bismuth suprisingly is not very poisonous compared to the fact that led is very poisonous, and so there are some suggestions that we should be exploring more the chemistry of bismuth as a catalist because if it works well then it can be used in chemical processes with much less danger than some of these other materials. - So if we can push it out from this old paper package then you can see it's packaged really quite nicely, here you can see the bismuth metal itself, bismuth is used in catalysis to attenuate selective reactions so perhaps we might use bismuth with a platinum group metal like paladium or platinum even to make chemistry work even more selectively, it's a really beautiful element then. Really nice, so we'll pop that back in there nice and safe. - What have you got there, where did that come from? - I bought it because it's so pretty, I bought it from a shop, I can't remember actually which shop now, but I collect these sorts of things. These very big pretty looking sort of metallic things and crystals and as you can see it's really nice and irradescent so it's got a tarnished oxide layer and it shines like all the colors of the rainbow which is really really pretty in my opinion. Lovely! Captions by www.SubPLY.com
