Contrast observations of ionized and neutral hydrogen in space. ...

[joe]

Contrast observations of ionized and neutral hydrogen in space.
 
  What will be an ideal response?

Question 2

Comparing the clouds of Earth and Venus, we find that:
 
  A) both are made chiefly of water vapor.
  B) ours lie in the troposphere, within 10 kilometer of our surface, but Venus has a higher troposphere, with its clouds about 40 kilometers high.
  C) like ours, they rotate around Venus slower than Venus rotates on its axis.
  D) Venus has much more carbon dioxide, so dry ice clouds dominate.
  E) Venus is too hot for clouds to form, so we see only a barren world telescopically.

[briezy]

Answer to Question 1

Emission nebula glow bright red from the ionized hydrogen around hot young stars, but most of the hydrogen is cooler and neutral and transparent; it can best be mapped from its 21 cm radio emission instead.

Answer to Question 2

B

[joe]

Thanks for the timely response, appreciate it

[chereeb]

YES! Correct, THANKS for helping me on my review