What is a quantity that describes only the magnitude

What effect does plate tectonics have an organic evolution

Vessels draining the myocardium of the heart, open primarily ,into which chamber?

Which plate boundary causes plates to collide forming mountain ranges, volcanoes, and island arcs? give an example of this type of plate boundary. 2. at which plate boundary do rifts and mid-oceans ridges form? give an example of this type of plate boundary. 3. at which plate boundary do plates slide past each other while moving in opposite directions? give an example of this type of boundary.