Question

Only iodine forms hepta fluoride $I{F}_7$, but chlorine and bromine give penta fluorides, The reason for this is :

• A. low electron affinity of iodide
• B. pentagonal bipyramidal structure of $I{F}_7$
• C. Larger iodine atom can accomodate more number of smaller fluorine atoms around it
• D. low chemical reactivity of $I{F}_7$

Answer 1

The correct option is C Larger iodine atom can accomodate more number of smaller fluorine atoms around it

Due to larger size, iodine atom can accomodate upto seven small fluorine atoms arround it . Due to smaller sizes of chlorine and bromine they cannot accomodate seven fluorine atoms i.e., steric factor dominate incase of chlorine and bromine central atoms. Hence correct answer is option (c).