Both He3 and He4 are important in the proton-proton cycle. How ...

[elizabeth18]

Both He3 and He4 are important in the proton-proton cycle. How are they different, and which comes first?
 
  What will be an ideal response?

Question 2

Which of these is NOT an argument for Cygnus X-1 being a black hole?
 
  A) The mass of the X-ray source is about 10 solar masses.
  B) It is the third strongest source of X-rays in the sky.
  C) The X-rays from the compact source vary in as little as a millisecond.
  D) Spectroscopic data suggests hot gas is flowing toward the X-ray source.
  E) The mass of the visible star is greater than that of the X-ray source.

[yotaSR5]

Answer to Question 1

Helium 3 has two protons and one neutron, and two of them collide in the last step of the proton-cycle to make helium 4 with two protons and two neutrons; they also release two extra protons.

Answer to Question 2

E

[elizabeth18]

YES! Correct, THANKS for helping me on my review

[6ana001]

TYSM