<span>i think its Uranium Dating </span>
<span>3Ca + 2AlPO4 -> 2Al + Ca3(PO4)2 . . .the coefficient for Ca is 3.</span>
According to the kinetic molecular theory for an ideal gas, all gas particles "<span>have collisions that decrease the total energy of the system" but this is not always the case. </span>
I think it is the first choice
Hope that helped!