Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?

(i) Au (ii) Cu

(iii) Na (iv) K

Which one of the following properties are not generally exhibited by ionic compounds?

Which of the following metals exist in their native state in nature?

(i) Cu

(ii) Au

(iii) Zn

(iv)Ag

Silver articles become black on prolonged exposure to air. This is due to the formation of:

Galvanisation is a method of protecting iron from rusting by coating with a thin layer of: