When does hydrogen first begin to fuse into helium in the star ...

[kodithompson]

When does hydrogen first begin to fuse into helium in the star formation process?
 
  A) when the cloud first begins to contract
  B) when the thermal pressure is trapped at the center of the cloud
  C) when the protostars undergoes convective contraction
  D) when the protostar undergoes radiative contraction
  E) only when the star reaches the main-sequence

Question 2

The area in the Sun's atmosphere located above the chromosphere (1,500 - 10,000 km) where the temperature rises dramatically is called the
 
  A) photosphere.
  B) corona.
  C) solar wind.
  D) transition zone.
  E) convection zone.

[josephsuarez]

Answer to Question 1

D

Answer to Question 2

D

[kodithompson]

Gracias!

[Liamb2179]

Excellent