For a main-sequence star of less than 0.4 M ? , what percentage of the mass of the core still remains as hydrogen after the thermonuclear furnace has transformed hydrogen into helium over its main-sequence lifetime?
A)75%
B)35%
C)25%
D)less than 1%

Question

Quizplus · Accepted Answer

For a main-sequence star of less than 0.4 M ε, the core temperature never gets high enough (less than 10 million K) to burn helium into heavier elements after the hydrogen is consumed. Therefore, less than 1% of the mass of the core still remains as hydrogen after the thermonuclear furnace has transformed hydrogen into helium over its main-sequence lifetime.

For a Main-Sequence Star of Less Than 0