In the image we can see that there are 1 phosphorus (P4) molecules and 7 fluorine molecules.
According to the stoichiometry of the reaction, one molecule of phosphorus (P4) and 6 molecules of fluorine (F2) are needed to form 4 molecules of PF3.
The answer is:
The limiting reagent is phosphorus (P4)
The number pf PF3 molecules formed is 4 and
The number of fluorine atoms/molecules in excess is 1.