Geologic evidence shows that earth's tectonic plates can move thousands of kilometers across the earth's surface. these movements a. do not change the earth's surface at all. b. occur gradually over millions of years. c. occur due to human activity. d. occur in one sudden movement.

they begin to vibrate harder causing the material that was solid to turn into a liquid i.e gallium or ice

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .