Answer :
Answer: 2.85 moles of flourine
Explanation:
find the atomic/molar mass of flourine on your periodic table.
multiply the given mass (54.1g) by (1 mole of flourine/atomic mass of flourine)
54.1g flourine * 1mole of flourine/18.998g flourine
(g flourine) in the above equation cancel each other.
54.1/18.998 = 2.85 mole of flourine