Here's how to calculate the number of moles in 45g of fluorine (F):

1. Find the molar mass of fluorine:

* The molar mass of fluorine (F) is approximately 19 g/mol. This means 1 mole of fluorine atoms weighs 19 grams.

2. Use the formula:

* moles = mass / molar mass

3. Plug in the values:

* moles = 45 g / 19 g/mol

* moles ≈ 2.37 mol

Therefore, there are approximately 2.37 moles of fluorine in 45 grams.