An ampholyte is a substance that can function as both an acid and a base, depending on the surrounding pH. A common example is an amino acid, which has both acidic (carboxyl) and basic (amino) groups.
Europium (Eu) resembles Calcium (Ca) in the following ways:
(A). Both are diamagnetic
(B). Insolubility of their sulphates and carbonates in water
(C). Solubility of these metals in liquid NH3
(D). Insolubility of their dichlorides in strong HCI
Choose the correct answer from the options given below: