When two different halogens react with each other, interhalogen compounds are formed. They can be assigned general compositions as XX’ , XX’_3, XX’₅ and XX’₇ where X is halogen of larger size and X’ of smaller size and X is more electropositive than X’. As the ratio between radii of X and X’ increases, the number of atoms per molecule also increases. Thus, iodine (VII) fluoride should have maximum number of atoms as the ratio of radii between I and F should be maximum. That is why its formula is IF₇ (having maximum number of atoms).

Which of the following is true about interhalogen compounds?

They are diamagnetic

Interhalogen compounds are diamagnetic in nature. This is because they have bond pairs and lone pairs. The A-X bond in interhalogen compounds is much weaker than the X-X bond in halogens, except for the F-F bond.