This topic contains a solution. Click here to go to the answer

Author Question: How is 21 cm radiation produced? What will be an ideal response? ... (Read 31 times)

chandani

  • Hero Member
  • *****
  • Posts: 541
How is 21 cm radiation produced?
 
  What will be an ideal response?

Question 2

What is the approximate chemical composition (by mass) with which all stars are born?
 
  A) three quarters hydrogen, one quarter helium, no more than 2 heavier elements
  B) half hydrogen and half helium
  C) 98 hydrogen, 2 helium
  D) 95 hydrogen, 4 helium, no more than 1 heavier elements



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

brittanywood

  • Sr. Member
  • ****
  • Posts: 355
Answer to Question 1

When the electron orbiting the proton for hydrogen flips its spin, the energy radiated has a wavelength of 21 cm., and is detected with radio telescopes.

Answer to Question 2

A




chandani

  • Member
  • Posts: 541
Reply 2 on: Jul 27, 2018
:D TYSM


atrochim

  • Member
  • Posts: 331
Reply 3 on: Yesterday
Gracias!

 

Did you know?

Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.

Did you know?

The highest suicide rate in the United States is among people ages 65 years and older. Almost 15% of people in this age group commit suicide every year.

Did you know?

Warfarin was developed as a consequence of the study of a strange bleeding disorder that suddenly occurred in cattle on the northern prairies of the United States in the early 1900s.

Did you know?

Automated pill dispensing systems have alarms to alert patients when the correct dosing time has arrived. Most systems work with many varieties of medications, so patients who are taking a variety of drugs can still be in control of their dose regimen.

Did you know?

To combat osteoporosis, changes in lifestyle and diet are recommended. At-risk patients should include 1,200 to 1,500 mg of calcium daily either via dietary means or with supplements.

For a complete list of videos, visit our video library