Bismuth (Bi) is a metal that is 86% as dense as led. At first glance it looks like a boring slab of metal, but when heated and then cooled, it crystallizes into beautiful shapes and colors. My partner Audrey and I wanted to observe this process first hand and see for ourselves just why bismuth was so interesting. We asked to be instructed by a group of students who had worked with bismuth only a few days prior, and with this we were ready to begin. After putting our safety goggles on and making sure a protective glove was in reach to handle hot materials, we were first instructed to break the (easily breakable) bismuth into pieces, and then shove the bits into two small cups that served as mini saucepans. After this we placed them on a hot plate and waited for melting to begin. Bismuth melts when it reaches 520.6 degrees fahrenheit, this is a bit of a wait, but once it was fully melted, (after about twenty minutes) we proceeded to turn the hot plate off. Before the cooling could begin, we had to scrape off this metallic film collecting on the surface of the molten liquid (kind of like the nasty film that collects on hot chocolate when it sits too long.) After that it was time to wait for it to cool. This is the hard part, there is guesswork involved, and if you don't catch it at the right time, it could add an extra hour to your experiment of reheating a hard bismuth. This is what happened to Audrey and I and our 30 minute project turned into a 1 hour 30 minute one. We were told to wait for the sides to look like they were hardening and the middle to not jiggle when we slightly nudged the table. The first time, we waited as long as we thought was right, but when we poured out the access liquid and then proceeded to try and break the bismuth out, it wouldn't budge. Feeling a little sad, but not defeated, we turned the hot plate back on and waited for it to melt again. After about 20 minutes of hard bismuth, Andrew stepped in with a blow torch and melted the bismuth to speed things up. We scraped of the film and let it cool yet again. This time we were paraniod and called a bismuth veteran over every five minutes or so to check in. We didn't wait to long thankfully, and when we broke it out of the cup, we didn't have very much, but we had a few really beautiful pieces. Below are some images of jewelry I made with what we extracted!
This lab was really interesting, the colors constantly changed at different heats, and there was never a boring moment. I wondered why this was and thought maybe it was something to do with light, it was almost holographic when hardened after crystalization. After doing a little research, I found out i was correct! On the surface of bismuth is a layer of oxide. When light touches different part of this layers, you will see the color changed.
From the shape to the colors, bismuth is stunning to work with. It's a classic example of why you shouldn't judge a book by it's cover! I definitely want to explore it greater in the future.
This lab was really interesting, the colors constantly changed at different heats, and there was never a boring moment. I wondered why this was and thought maybe it was something to do with light, it was almost holographic when hardened after crystalization. After doing a little research, I found out i was correct! On the surface of bismuth is a layer of oxide. When light touches different part of this layers, you will see the color changed.
From the shape to the colors, bismuth is stunning to work with. It's a classic example of why you shouldn't judge a book by it's cover! I definitely want to explore it greater in the future.