What is the correct way to represent the ionic compound sodium fluoride?

(Na)+. (Fl)-

Explanation:

Na=2.8.1

Fl=2.7

Sodium will give fluorine its one atom to be a cation + with a configuration of 2.8 while fluorine will be a anion - with a configuration of 2.8

I don't know how to add a picture, so I might not explain this well.

Explanation: You put Na in the first box. Then you put F in the center of the second box because it gained one electron from Na. Then in the third box you put Na [+] because it lost one electron so it's now an cation(has a positive charge) because it lost a valence electron. In the last box you would put F [-] because it gained one electron so it's now an anion( has a negative charge) because it gained a valence electron. F now has 8 valence electrons and Na has 8 as well therefore they're both balanced.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)