750 million years ago, there was enough Uranium-235 present in Oklo, Gabon to have a natural fission reacton occur and generate a chain reaction. If there is currently 50kg of U-235 present in Oklo, how much must have been present 750 million years ago when the reaction took place? A) 50 kg B) 100 kg C) 200 kg D) 375 kg B 100kg because i put 50 and it was wrong.

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.