daffyduck
BaNa[sub]2[/sub]
I don’t think it is anything. Both of those elements (barium & sodium) have positive valences so how could they combine?
That’s exactly what all of us who answered the question said and we were marked wrong but given the three points extra credit.
Ba - Na - Na is a Banana!
daffyduck: My 11th grade chemistry teacher, who had no sense of humor whatsoever, put that on a quiz too, along with HiHoAg. I got that one, but I didn’t get BaNa[sub]2[/sub] for some reason. I asked about it, and she said ‘it’s a joke’. I also had a HS chem teacher who wore socks with sandals. My college professors were far less interesting.
I have a few more names:
oxyd of inflammable air
calx of inflammable air
hydrated dephlogisticated air
calcined phlogiston
All of these can be interchanged. They come from the period where people finally understood they couldn’t make gold from lead, but still didn’t understand as much chymistry as they thought they did. None of those terms would actually have been used, because the formula for water wasn’t established until Canizzaro worked out the correct atomic weights around 1858. Before that there was substantial confusion arising from incorrect beliefs about elements needing to combine in whole-number ratios and the impossibility of diatomic gases. (link; note especially the picture of Amodeo Avogadro, one of the least attractive scientists ever)
A fruit.
As in “Time flies like an arrow. Fruit flies like a BaNa[sub]2[/sub].”
I call it “liquid ice.”
Thanks for explaining. 
And yes, I did see the stacked atomic and isotope numbers in a text on nuclear reactions.
Yeah, I made it up years ago as a joke and thought this thread was a good place to mention it. 
:o
I always thought “hydrogen oxide” was the best, since it’s not necessary to specify it’s “dihydrogen monoxide”. H[sub]2[/sub]O is the only “hydrogen oxide” there could be, strictly speaking.