Helium originates from
A) stellar nucleosynthesis only.
B) the Big Bang only.
C) mostly from stellar nucleosynthesis with a small contribution from the Big Bang.
D) radioactive decay of elements heavier than carbon.
E) mostly from the Big Bang with a small contribution from stellar nucleosynthesis.
Question 2
As an interstellar cloud of hydrogen gas shrinks in size, its rate of rotation
A) increases, because its total energy is conserved.
B) decreases, because the force of gravity strengthens as the cloud shrinks.
C) increases, because its angular momentum is conserved.
D) decreases, because its angular momentum is conserved.
E) increases, because the force of gravity strengthens as the cloud shrinks.