Match List-I with List-II

(a) Ba	(i) Organic solvent soluble compounds
(b) Ca	(ii) Outer electronic configuration 6s$$^2$$
(c) Li	(iii) Oxalate insoluble in water
(d) Na	(iv) Formation of very strong monoacidic base

Choose the correct answer from the options given below:

We match each element with its characteristic property.

(a) Ba (Barium): Barium belongs to Group 2 (alkaline earth metals), period 6. Its outer electronic configuration is $$6s^2$$ — matching (ii).

(b) Ca (Calcium): Calcium sulphate and calcium oxalate are both sparingly soluble in water. Specifically, calcium oxalate (CaC$$_2$$O$$_4$$) is insoluble in water and is used in the gravimetric estimation of calcium — matching (iii).

(c) Li (Lithium): Lithium, unlike other alkali metals, forms organic solvent-soluble organolithium compounds (e.g., butyllithium dissolves in hydrocarbons). This diagonal relationship with Mg means its salts (like LiCl) are often soluble in organic solvents — matching (i).

(d) Na (Sodium): Sodium hydroxide (NaOH) is a very strong monoacidic base. It is a strong base that fully dissociates in water and is monoacidic (one OH$$^-$$ per formula unit) — matching (iv).

The correct matching is (a)-(ii), (b)-(iii), (c)-(i) and (d)-(iv), which is option (1).