Observationally, how can we tell the difference between a ...

[P68T]

Observationally, how can we tell the difference between a white-dwarf supernova and a massive-star supernova?
 
  A) A massive-star supernova is brighter than a white-dwarf supernova.
  B) A massive-star supernova happens only once, while a white-dwarf supernova can repeat periodically.
  C) The light of a white-dwarf supernova fades steadily, while the light of a massive-star supernova continues to brighten for many weeks.
  D) The spectrum of a massive-star supernova shows prominent hydrogen lines, while the spectrum of a white-dwarf supernova does not.
  E) We cannot yet tell the difference between a massive-star supernova and a white-dwarf supernova.

Question 2

What are the two geological features that appear to set Earth apart from all the other terrestrial worlds?
 
  A) a dense core and plate tectonics B) mantle convection and a thick atmosphere
  C) significant volcanism and tectonics D) plate tectonics and widespread erosion

[johnpizzaz]

Answer to Question 1

D

Answer to Question 2

D

[P68T]

TYSM

[robbielu01]

Excellent