Only iodine forms hepta-fluroide `IF_(7)`, but chlorine and bromine give penta-flurorides. The reason for this is:

Options

A. Low electron affinity of iodine.
B. Unusual pentagonal bipyramidal structure of `IF_7`.
C. That the large iodine atom can accommodate more number of smaller fluorine atom around it.
D. Low chemical reactivity of `IF_7,`

Answer

C

Explanation

Due to larger size of iodine atom it can accommodate upto seven small fluorine atoms around, it while due to smaller sizes of chlorine and bromine atoms do not accommodate seven fluorine atoms, i.e., steric factor dominate in case of chlorine and bromine.