What element X is most likely to react to form the compound XF5?

carbon

antimony

chlorine

calcium

and I already thought it was helium but I was wrong. Not helium because it doesnt form a +5 oxidized state

antimony. it has +3,+5,-3 so yeah. the others carbon+2,+4,-4, chlorine +1,+5,+7,-1 but -1 is the most often so it isnt Cl, calcium +2.
respond is Ca3X2. Na reacts with X and varieties Na3X. meaning that Na has valancy a million and X has valancy 3, so 3 atoms of Na reacts with a million atom of X to end its valancy. for that reason they type the ionic compound Na3X. similarly, all of us comprehend that Ca has valancy 2. So the ionic compound with X will could be Ca3X2, which shows that X has valancy 3.
Antimony

Source(s): MasteringChemistry problem (I got it right)
chlorine