The geological theory that states that pieces of earth's crust are in constant slow motion

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

Which statement is true regarding the diagram of circle p? the sum of y and z must be 2x. the sum of y and z must be x. the difference of z and y must be 2x. the difference of z and y must be x

Which question could be best answered using the process of scientific inquiry? do different plates have different rock compositions? why did it take so long to develop the theory of plate tectonics? what are different cultural myths caused by plate tectonics? do plates move intentionally to cause volcanic eruptions?