Name two metals which form amphoteric oxides.

10 Give the names and formulae of (a) two acidic oxides, and (b) two basis oxidics. 11 What name is given to those metal oxides which show basis as well as acidics behavior ? 13 A copper coin is kept immersed in a solution of silver nitrate for some time. What will happen to the coin and colour of the solution ? 14 Which property of copper and aluminium makes them suitable:

(a) For making cooking utensils and boilers?

(b) for making electric wires?