Final answer:
The element with atomic mass 19 is potassium, belonging to Group 1 and is an alkali metal. It forms ionic chlorides due to its valency of 1, not 2, and therefore statement "d" in the question is incorrect.
Step-by-step explanation:
An element with atomic mass 19 is likely to be potassium (K), which has an atomic number of 19. Given the characteristics:
It belongs to Group 1 of the periodic table, not Group II. Therefore, statement "b" is incorrect.
It is an alkali metal, which is confirmed by its placement in Group 1.
It typically forms ionic chlorides, such as KCl, so statement "c" is correct.
The valency of potassium is 1, not 2, hence statement "d" is incorrect.
As a Group 1 element, potassium easily loses one electron to form a cation with a +1 charge. The notion of potassium having a valency of 2 is therefore incorrect.