Suppose a scientist holds a press conference at which he claims ...

[nautica902]

Suppose a scientist holds a press conference at which he claims that 10 of the matter in the Milky Way is in the form of dust grains. Does his claim seem reasonable? Why or why not?
 
  A) It is reasonable because we already know that interstellar dust obscures our view through the disk of the galaxy.
  B) The 10 figure is too high because there are not enough heavy elements to make that much dust.
  C) It seems reasonable as long as we assume that red giant starswhich produce dust grains in their stellar windsare more common than we thought.
  D) The 10 figure is too low because most of the mass of the galaxy is in the form of interstellar dust.

Question 2

The ________ are two layers of charged particles trapped by our magnetic fields.
 
  Fill in the blank(s) with correct word

[AmberC1996]

Answer to Question 1

B

Answer to Question 2

Van Allen radiation belts

[nautica902]

YES! Correct, THANKS for helping me on my review

[duy1981999]

Gracias!