Chromatography is a way of separating a mixture of chemicals which are in gas or liquid form. when the paper absorbs the liquid, the different colours from the colouring pencils will not be separated because they are insoluble solid pieces,also because they are solid the colours will not be able to creep up the paper which is why chromatography can not be used to separate different coloured pencils.
Halogens have seven valence electrons and reqires one more electron to complete its octet
Answer:

Explanation:
Silver chloride precipitates out because it has a low value of Ksp.
Answer:
c. Kay's rule
Explanation:
Kay's rule -
The rule is used to determine the pseudo reduced critical parameters of mixture , with the help of using the critical properties of the components of a given mixture .
The equation for Kay's rule is as follows ,
PV = Z RT
Where Z = The compressibility factor of the mixture .
Hence from the given options , the correct answer is Kay's rule .