Why does the Main Sequence part of a star's life end?

A: Much of the mass of the star has evaporated
B: The Hydrogen in the core is exhausted
C: The Helium in the core is exhausted
D: The temperature drops so that nuclear reactions are no longer possible
E: The gravitational force is no longer large enough to balance the pressure


Ans: B: The Hydrogen in the core is exhausted

Physics & Space Science

You might also like to view...

Constant Acceleration Kinematics: A soccer ball is released from rest at the top of a grassy incline. After 6.4 seconds the ball has rolled 91 m with constant acceleration, and 1.0 s later it reaches the bottom of the incline.(a) What was the ball's acceleration?(b) How long was the incline?

What will be an ideal response?

Physics & Space Science

A conclusion of the Michelson-Morley experiments was that

A. interference of EM-waves does not happen. B. the ether doesn't exist. C. Galilean relativity holds. D. light has momentum. E. light has no momentum.

Physics & Space Science

What part of the Apollo spacecraft actually returned to Earth?

a. descent rocket b. lunar module c. rocket boosters d. command module e. support stage

Physics & Space Science

When sound travels faster at ground level than higher in the air, sound tends to bend

A) upward. B) downward. C) neither of these

Physics & Space Science