if i am correct it shall be 12. because i am thinking, 1 mole = 1 ar.
Add proton + neutrons = Mass 37
Proton is same as your atomic mass= 17
If you go on the periodic table look up 17 and it will give u the letter.
There are 48.72 g Fluorine ions
<h3>Further explanation
</h3>
Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements
In the same compound, although from different sources and formed by different processes, it will still have the same composition/comparison
%F in CaF₂ :

mass of Fluorine :

So mass Fluorine ions(2 ions F in CaF₂⇒Ca²⁺+2F⁻) :

<span>The superscripts in an electron configuration represents the number of electrons and protons in an element. </span>