A natural force of attraction exerted by the earth upon objects, that pulls objects towards earth's center is called<u> </u><u>G</u><u>ravitational</u><u> </u><u>force</u><u> </u><u>.</u>
I have one reason the reaction take place faster because the molecules are going at a faster pace because the temperature is rising
16 kilometers is the answer i came up with. hope this helps.