Question

LiF is ionic in nature will another halides of lithium are covalent in nature explain

Answer 1

LiF is ionic in nature while other halides like LiI is is covalent in nature because, according to Fajan's rule, as size of cation increase and that of anion decrease,polarising power increases and thus covalent character increases.

(In LiF, Li is smaller in size and I is larger in size)

Answer 2

Hello friend ,

As per the Fajan's rule that molecule is said to be more covalent which has

1)Smaller cation ,Bigger anion ,and has a bigger charge on both the ions

2)It follows a PNGC which has exceptional cases like (Zn2+, Hg2+,Cd2+,Cu+,Au+,Ag+)

*these elements have noble gases like configuration ns2 np6 nd10

Thus here in this case of LiF the cation Li falls in the first group and is the" smallest comparable" element in that group while F is the smallest anion present from it's respective group therefore as per Fazan's rule the molecule is ionic as the Cation is small but the anion is also small which makes it ionic ,but in other cases like LiCl ,LiBr ,LiI the anion is bigger that appropriately fits into the Fazan's rule .