This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Interstellar gas is composed mainly of A) some hydrogen, but mainly carbon dioxide. B) 10 ... (Read 83 times)

Jipu 123

  • Hero Member
  • *****
  • Posts: 569
on: Jul 27, 2018
Interstellar gas is composed mainly of
 
  A) some hydrogen, but mainly carbon dioxide.
  B) 10 hydrogen, 90 helium by numbers of atoms.
  C) 90 hydrogen, 9 helium by weight.
  D) ammonia, methane, and water vapor.
  E) only hydrogen.

Question 2

Why did Hubble have to rely on Cepheids to find the distance to M31, unlike Shapley's use of RR Lyrae stars with the Milky Way?
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

blfontai

  • Sr. Member
  • ****
  • Posts: 327
Reply #1 on: Jul 27, 2018
Answer to Question 1

C

Answer to Question 2

The RR Lyrae stars were not bright enough to be seen from the distance of the Andromeda Galaxy, so Hubble used longer-period Cepheids in the spiral arms which were also much more luminous and showed up on his photos.


Jipu 123

  • Member
  • Posts: 569
Reply 2 on: Jul 27, 2018
Great answer, keep it coming :)

elyse44

  • Member
  • Posts: 319
Reply 3 on: Yesterday
Gracias!

« previous next »
 

Did you know?

Lower drug doses for elderly patients should be used first, with titrations of the dose as tolerated to prevent unwanted drug-related pharmacodynamic effects.

Did you know?

There are 60,000 miles of blood vessels in every adult human.

Did you know?

Hippocrates noted that blood separates into four differently colored liquids when removed from the body and examined: a pure red liquid mixed with white liquid material with a yellow-colored froth at the top and a black substance that settles underneath; he named these the four humors (for blood, phlegm, yellow bile, and black bile).

Did you know?

Patients who have been on total parenteral nutrition for more than a few days may need to have foods gradually reintroduced to give the digestive tract time to start working again.

Did you know?

It is difficult to obtain enough calcium without consuming milk or other dairy foods.

Changes in Earth's atmospheric carbon dioxide levels over geological time. Changes in Earth's atmospheric carbon dioxide levels over geological time.
Hydrogen Bonding and the Properties of Water Hydrogen Bonding and the Properties of Water
Energy Level Diagram of Hydrogen Energy Level Diagram of Hydrogen
How to detemine the PH of a solution when given the hydrogen concentration How to detemine the PH of a solution when given the hydrogen concentration
Fate of the Amino acid carbon skeletons Fate of the Amino acid carbon skeletons
Covalent bond- carbon rings Covalent bond- carbon rings
Video: Role of the respiratory system - effect of altered ventilation rates

For a complete list of videos, visit our video library