(b) Choose the correct answer from the choices (A), (B), (C) and (D):
(i) The property which is characteristic of an electrovalent compound is that:
(A) it is easily vaporized
(B) it has a high melting point
(C) it is a weak electrolyte
(D) it often exists as a liquid
(ii) When a metal atom becomes an ion:
(A) it loses electrons and is oxidized
(B) it gains electrons and is reduced
(C) it gains electrons and is oxidized
(D) it loses electrons and is reduced
(iii) Which of the following hydroxides is not an alkali?
(A) ammonium hydroxide
(B) calcium hydroxide
(C) copper hydroxide
(D) sodium hydroxide
(i) Electrovalent compounds have high melting point. Hence, the correct answer is option (B).
(ii) A metal looses electrons and is oxidised to form an ion. Hence, the correct answer is option (A).
(iii) Copper hydroxide is insoluble in water; therefore, it cannot be considered to be an alkali. Hence, the correct answer is option (C).