Which chemical equation best describes the reaction of potassium metal with fluorine gas to form solid potassium fluoride? 

A. K(s) + F2(g) → KF2(s)

B. K(s) + F(g) → KF(s) 

C. K2(g) + F2(g) → 2 KF(s)

D. 2 K(s) + F2(g) → 2 KF(s) 

I guessed B