Why does boron fume in moist air? Is the following accurate?

I initially guessed it was due to the formation of $\ce{H3BO3}$ but am now doubtful. Does it have anything to do with $\ce{HCl}$ formation? If the question referred to a boron halide, I could answer with that. Either the question is wrong, or my guess is. What's accurate?


I'd appreciate any help.
Grade 11 Chem.


