Question

Which of the following option(s) is/are correct regarding ionic character of metal halides?
Here $M$ is a monovalent metal

• A. $MF$ has the least ionic character
• B. $MI$ has the least ionic character
• C. $MF$ has the highest ionic character
• D. $MI$ has the highest ionic character

Answer 1

Answer: (B), (C)

$MF$ has the highest ionic character

According to Fajan's rule, as the size of anion increase its ionic character decrease. Since the size of $F^{-}$ is the lowest among halides hence $MF$ has the highest ionic character.
The order of ionic charcter among metal halides is:
$MF>MCl>MBr>MI$