If the redshift of a quasar were 3, at what wavelength would the 486.1-nm line of hydrogen appear in ...

If the redshift of a quasar were 3, at what wavelength would the 486.1-nm line of hydrogen appear in the quasar's spectrum?
 
  What will be an ideal response?

Question 2

Why do higher-mass stars live shorter lives on the main sequence than lower-mass stars?
 
  a. Higher-mass stars burn through their nuclear fuel faster.
  b. Lower-mass stars don't get their energy from that same nuclear fusion source as higher-mass stars.
  c. Higher-mass stars have less hydrogen fuel to burn.
  d. Lower-mass stars spend a longer time evolving to the main sequence.
  e. All of the other choices are false.

Question 3

_________________ galaxies are very luminous at X-ray and ultraviolet wavelengths and have broad emission lines in their spectra.
 
  Fill in the blank(s) with correct word