i. Arrange the following metals in the order of increasing reactivity.
ii. Hence state which of them can be extracted by electrolysis.
iii. Why is zinc said to be amphoteric.
Solution:
i. Au, Sn, Zn, Mg, Ca, Na
ii. Na, Ca, Mg
iii. Zn is amphoteric because it reacts/forms an oxide which can react with acid and alkalis to form stable salts.