Earth space science important quiz so i can move ! im stuck on 7 !

14. which layer of earth is liquid? a .crust b. inner core c. outer core d. lower mantle
search
15. the motion of which layer of earth is the driving force that creates plate tectonics? a. crust b. outer core c. lower mantle d. asthenosphere.
16. select all the properties that increase as you go deeper inside earth. a. density b. pressure c. temperature d. amount of iron e. amount of oxygen f. number of earthquakes
18. which of the following is not a source of earth's internal heat? a. mantle convection b. radioactive substances c. gravitational contraction d. past bombardment by asteroids.
19. the lack of plate tectonics on other planets in our solar system likely means which of the following must be true? a. no other planet has a warm interior. b. earth has more layers than any other planet. c. earth is the only planet with a magnetic field. d. no other planet has a solid crust over a moving upper mantle.
20. which layer of earth is responsible for creating earth's magnetic field? a. crust b. outer core c. lower mantle d. asthenosphere