The correct statements among the following regarding inter halogen compounds

When a halide ion combines with halogen or inter halogen compound poly halide ions  are formed

The b.pts of  $X{Y}_n$  type of inter halogen compounds increase with increase in the  difference in electro negativities of X and Y (except IF)

All inter halogen compounds have even number of halogen atoms and are diamagnetic

During, self ionization of inter halogen compounds, ions having odd number of halogen  atoms are formed