1. (20 pts) amount of your element: assume the earth is a sphere with a radius of 6,400km and the crust is 25km thick. a. (5 pts) explain the distinction between reserves and the resource base. b. (5 pts) for your element (final project or pick one if you do not have one yet) calculate how much we have in the earths crust. ignore the oceans as a source of your element (even if it is a source) c. (10 pts) for your element. a company wants to mine this element from a near earth object. cost per kg to put an object in space on an atlas v rocket is $27,000/kg. assume that the weigh of equipment that must be landed on the near earth object is 2,000kg. if the abundance of the element is twice that on earth, how many kg need to be on the near earth object to hit the break-even point? (assume all equation shown in lecture on earth apply to space mining.)