An element X reacts with hydrogen, when heated, to form a covalent hydride H₂X. If H₂X has a smell of rotten eggs, the element X is likely to be:

72 Out of aluminium, copper, calcium and tin, the most reactive metal is: 73 The least reactive metal among the following is: 75 Out of the following oxides, the amphoteric oxide is: 76 The metals which can produce amphoteric oxides are: