Li shows diagonal relationship with
Diagonal relationship between elements refers to the relationship between diagonally adjacent elements in the second and third periods due to similarity in their size.
Lithium is different from other alkali metals due to its small size but since its size resembles with that of magnesium, it shows a diagonal relationship with magnesium.
The correct option is A: Mg
Aqueous solution of borax is
Borax (Na[ B4O5(OH)4].8H2O) is a salt of boric acid (H3BO3) and sodium hydroxide (NaHO) base.
Borax, also called sodium borate, sodium tetraborate or disodium tetraborate is basically a salt of weak acid and a strong base.
Borax, when dissolved in water, ionizes and hydrolysis of borate ion formed gives HO- and boric acid.
Since boric acid is weak acid and sodium hydroxide is strong, the aqueous solution is alkaline in nature.
The correct answer is C: basic