Final answer:
When bismuth reacts with fluorine, the product is bismuth trifluoride, BiF3. Bismuth commonly forms compounds in a +3 oxidation state, and the formation of BiF3 is similar to how other group 15 elements react with fluorine.
Step-by-step explanation:
When bismuth, a chemical element with the symbol Bi and atomic number 83, reacts with fluorine, the product of the reaction is bismuth(III) fluoride. Each fluorine atom has seven valence electrons and is highly electronegative, while bismuth has three valence electrons available for bonding. In the case of bismuth, the most common oxidation state is +3, which means it typically forms compounds where it shares three electrons with other elements.
Just like the reaction in which boron trifluoride (BF3) is formed by the direct reaction of boron with fluorine, bismuth reacts with fluorine to form bismuth trifluoride (BiF3). Bismuth trifluoride is the expected product because bismuth has a tendency to form compounds in which it holds a +3 oxidation state, analogous to other elements in group 15 like antimony, which forms antimony trifluoride (SbF3).
The correct answer to the question posed by the student is B: BiF3.