- See charge on ion is -1 .
Hence it has taken 1 electron
Now first look at EC of Fluorine(F)

- Now one electron added .hence no of electrons is 10now
Look at the EC

Or
![\\ \bull\sf\dashrightarrow [He]](https://tex.z-dn.net/?f=%5C%5C%20%5Cbull%5Csf%5Cdashrightarrow%20%5BHe%5D)
Option C is correct.
Answer:
put a salt into the beakers
<span>You can find
the number of moles in equilibrium if you got the chemical reaction correctly. Make
sure that you got the exact chemical formula of the substance that is reacting
and the yielded product. If you got them, balance the chemical reaction. If the
chemical reaction is balanced, the system is in equilibrium. You can find the
number of moles in equilibrium at the coefficients of the chemical substances
you are balancing. For example, N2 + 3H2 -> 2NH3. The number of moles of N2
is 1, H2 is 3 and NH3 is 2.</span>