Which of these processes best to maintain the composition of the mantle? (1) the cyclic movement of the liquid in the mantle
(2) the cyclic movement between the mantle and the crust
(3) the interaction between the inner core and the mantle
(4) the interaction between the outer core and the mantle

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.