Briefly describe the star-gas-star cycle. What will be an ...

[james]

Briefly describe the star-gas-star cycle.
 
  What will be an ideal response?

Question 2

Suppose it is full Moon. What phase of Earth would someone on the Moon see at this time?
 
  A) Full Earth
  B) New Earth
  C) First quarter Earth
  D) Earth does not go through phases as seen from the Moon.

[Melissahxx]

Answer to Question 1

During a star's lifetime, it fuses hydrogen into helium and helium into carbon. If it is more massive, it also creates heavier elements, up to iron, by fusion, and even heavier elements, up to uranium, during a supernova event. When the star ends its life as a planetary nebula or in a supernova explosion, it disperses these elements into the interstellar medium. The interstellar medium thus gains these heavier elements and has a smaller proportion of hydrogen but a larger proportion of heavier elements than it did before. The interstellar medium cools, forms molecular clouds, and then forms new stars, which are made out of the material of the interstellar medium.

Answer to Question 2

B

[james]

Gracias!

[coreycathey]

Excellent