Borax glass beads - who knew?

One of the issues that we run into with our material science students is that their attendance in awful. We teach them in a largely hands-on, lab-based class, and they don't come to school as regularly as we would like them to.

To work around that problem, we often try to find - or we're beginning to produce our own - videos showing what we did in lab. Yes, we want the students to be present and do the lab on their own. Second best is to have them come in and make up the lab outside of class, but that's not always possible - or something they're willing to do. The final option is to just say 'watch this video and answer the questions.'

This past year I went looking for a video showing our borax bead lab and didn't have much luck.

Along the way, however, I learned that there's a chemical analysis technique to identify ions in solution that's pretty similar to our borax bead lab. The technique was apparently invented by Jöns Jacob Berzelius in 1812 and involved forming a colorless borax bead on a platinum (or nichrome) wire. The colorless bead is then dipped lightly into a solution and reheated. Each ion them produces a characteristic color in the oxidizing and reducing portion of the flame.

It's remarkably similar to what we're doing in class, though we're getting the atoms and ions from the wire directly. Which leaves me with a question - we get a color from nichrome wire, but the test directions suggest that a colorless bead can be produced from the nichrome wire. Can anyone explain that seeming contradiction? Are we just heating our bead longer than recommended in the test protocol?



Notice the paper notes written in an Indian language.



Interesting to use a soda lime glass rod as the substrate for the borax bead.



I like the colors.



Interestingly, many of the videos I found explaining the test were taught by Eastern European or Indian speakers. I assume the borax bead test has fallen out of favor in the US - because of more instrumentation availability - but is still part of a chemistry curriculum in other nations?



Some ions apparently require the use of UV light to distinguish their identities.