kindly asking for help with these two questions!

3. Answer the following: (a) What factors affect the isomorphic substitution of one element for another in a crystal structure? (b) Why is it more difficult for a cation from solution to displace potassium (K+)from the interlayer spaces of beidellite than from montmorillonite? (c) How does illite differ in structure from (i) mica and (ii) smectite? 4. Write a balanced reaction for the transformation of Orthoclase =KAlSi3O8 to Beidellite =K0.5[Si3.5Al0.5]Al2O10(OH)2