Oxidation number of pf3

Answer 1

3
3 is the oxidation state of phosphorus in PF3.

Answer 2

I assume you mean PF3. P is -1 each for a total of -3 which makes P +3.

Answer 3

Correct @DrBob222, that is exactly what I meant.

Answer 4

oops. But I made a typo. I wrote this:
I assume you mean PF3. P is -1 each for a total of -3 which makes P +3. That isn't correct. I should have written:
F is -1 each for a total of -3 which makes P +3.

Answer 5

Yes.