A pure salt contains an unknown metal cation (M) and the sulfate anion, where M belongs to either group IA or IIA. 1.42 g of this salt was dissolved in water and treated with an excess of aqueous calcium chloride resulting in the formation of a precipitate. The precipitate was collected, dried and found to weigh 1.36 g. Determine the atomic mass of M and identify M.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.