In a large sampling of stars, the largest group represented in ...

[jessicacav]

In a large sampling of stars, the largest group represented in the H-R diagram will be the main sequence stars. Why are they so common?
 
  What will be an ideal response?

Question 2

The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that
 
  A) erosion destroyed the smaller craters that formed on the basin.
  B) Mercury's atmosphere prevented smaller objects from hitting the surface.
  C) only very large impactors hit Mercury's surface in the past.
  D) the Caloris Basin formed toward the end of the solar system's period of heavy bombardment.
  E) the Caloris Basin was formed by a volcano.

[jaaaaaaa]

Answer to Question 1

Like the Sun, they are young enough to have most of their initial hydrogen still not fused into helium; they will not evolve off the main sequence until the helium builds up a lot. Since hydrogen is by far the most abundant element and the easiest to fuse, most stars are going to use it as their major fuel, as long as the supply lasts. Stars spend the vast majority of their life spans on the main sequence.

Answer to Question 2

D

[jessicacav]

Excellent

[mcarey591]

TYSM