is the following true order or not?

Answer

A, C, D

Explanation

Consider the factors on which these properties depend:
(A) Cation is smaller while anion is bigger than its parent atoms.
(B) Correct order is `CI gt F gt Br gt I`.
(C ) Cation is smaller as it is formed by the loss of electron(s). The anion is formed by the gain of electron(s). The size of anion increases with increase in charge on anion i.e. as the `Z//e` ratio decreases the size increases.
(D) Across the period the size decreases and nuclear size increases. So, ionisation energy increases. However, the first ionisation energy of `Mg` is greater than `AI` because of high penetration power of `2s^(2)` electrons of `Mg` as compared to that of `2p^(1)` electron of `AI`.