Explain the geometry of PCl5 molecule and account for its high reactivity

In PCl5, in addition to equitorial bonds which lie in the same plane ,there are axial bonds. Since it suffers more repulsion it is longer than the other bonds. Also these are weak bondsand therefore these bonds can break easily . Because of these reasons,PCl5 is very reactive.

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.