Author Question: Suppose you read somewhere that 10 percent of the matter in the Milky Way is in the form of dust ... (Read 27 times)

Engineer · **on:** Jul 27, 2018

Suppose you read somewhere that 10 percent of the matter in the Milky Way is in the form of dust grains. Should you be surprised? If so, why?

A) Given how easily dust grains can form, 10 percent is a surprisingly low fraction.
B) The fraction of 10 percent is surprisingly high because dust grains can form only at low temperatures.
C) There is nothing surprising about the 10 percent figure because dust grains are the material from which stars are born.
D) The fraction of 10 percent cannot be correct. Dust grains are solid and only 2 percent of the matter in the galaxy is made of anything besides hydrogen and helium.

Question 2

The chromosphere is faint because of its low density.

Indicate whether the statement is true or false