If plate tectonics is what builds up Earth's mountains and ...

[Caiter2013]

If plate tectonics is what builds up Earth's mountains and continents, then what process tears them down?
 
  a. convection
  b. volcanism
 c. cratering
 d. erosion
 e. accretion

Question 2

What produces the coronal gas?
 
  What will be an ideal response?

[ultraflyy23]

Answer to Question 1

d

Answer to Question 2

1) Astronomers have evidence that most coronal gas is produced when massive stars die violently in supernova explosions. Although they are rare, such explosions blast large amounts of very hot gas outward in expanding bubbles. 2) Gas flowing away from very hot, young stars can also produce coronal gas. In some cases, neighboring bubbles of coronal gas may expand into each other and merge to form larger volumes called superbubbles.

[Caiter2013]

Thanks

[ultraflyy23]

Welcome