Hi aspirant,

Both the chapters you have mentioned come under physical chemistry of class 11. You can definitely study classification of elements and periodicity chapter without studying the atomic structure but you would have to study some more topics from the previous chapters as it would be handy in this case. While you would be studying the properties of rows and columns you would need the use of concepts from previous chapter such as electron gain enthalpy and electron affinity but this is not a major issue because 95% of the chapter has no relation with the previous one.

Hope it helps!