What layer of the atmosphere is the least dense

Hey, I learned this in science a few weeks ago!!

The least dense layer is the exosphere which is the outermost layer of the atmosphere.


In my science book it says, "it is least dense because it is farthest from the earth, whose gravitation force decreases in accordance with the inverse-square law. Since molecules and ions in this region have a better-than-even chance of escaping from the gravity of the earth, many of them do escape, to be replace by infalling matter from space itself, or by atmospheric matter from the layers below."

Hope this helps

Where is the following?

The reaction 2kalsi3o8 + 2(h+ + hco3-) + h2o  →  al2si2o5(oh)4 + 2k+ + 2hco3- + 4sio2 shows that feldspar kalsi3o8 is chemically altered by hydrolysis to form chalky-looking clay mineral kaolinite al2si2o5(oh)4. the chemical breakdown of potassium feldspar due to exposure to acidic water results to the mineral binding with the water molecule to become kaolinite with silica and potassium and bicarbonate ions in solution.