The nuclear process in which helium "burning" occurs in the deep interiors of red giant stars produces what?

Question

A) carbon and oxygen nuclei
B) hydrogen nuclei by fusion or splitting of helium nuclei
C) The nuclear mass is totally transformed by E=mc^2 into pure energy
D) iron nuclei

Answer 1

The answer is A, but I'll give you a more complete answer.

1. For most of their lives as red giants, stars with masses like that of the Sun DON'T "burn" helium at all. They ascend the red giant branch (RGB) with degenerate, non-burning helium cores, surrounded by a HYDROGEN-"burning" shell.

This long stage of RGB ascent (takes 1 - 2 x 10^9 years) only ends when helium is finally "ignited" in what turns out to be an unstable way, that is known as the "helium flash.". For a brief time, the deep, central nuclear energy "luminosity" reaches 10^12 - 10^13 that of the Sun, actually exceeding the visible luminosity of the entire galaxy these stars are in!

However, despite the rather misleading name, the "helium flash," NONE of this huge release of energy actually gets out of the star. Instead, it digs the degenerate helium core out of the deep gravitational well it was previously digging for itself. The star makes a fairly rapid transition to the "horizontal branch," where the star can now live for another relatively extended time of several x 10^7 to ~ 10^8 years. This stage of stellar evolution was first understood in a breakthrough paper in 1966.

During the entire "helium flash," some 2 - 3 % of the central helium is converted into carbon and oxygen nuclei.

2. For massive stars (masses greater than about 2.5 solar masses), the situation is different. They head for the red giant branch without ever becoming degenerate in their deep interiors. Helium "burning" begins in a stable way, and the transformation into carbon and oxygen proceeds at a steady rate, during a much longer existence as a red giant.

While you only asked for a multiple choice answer, I thought you might be interested in more background.

Live long and prosper.

Answer 2

stress motives fusion. The solar is somewhat made from hydrogen and helium. Hydrogen is the least complicated component contained in the universe, having purely one proton and one neutron. It also makes and breaks molecular bonds extra surely than different aspects. The solar replaced into created at the same time as gravity presented adequate hydrogen at the same time so as that the brilliant stress fused the hydrogen at its center into the 2d lightest component contained in the universe, helium (2 protons and a couple of neutrons). This fusion prevents the solar's remember from collapsing even extra, and finally each and each and every of the solar's hydrogen will change into helium, at which aspect it truly is going to initiate fusing helium into- i imagine lithium is next. that's likewise at the same time as the solar turns redder and expands to almost the length of one Earth orbit.

Answer 3

Eventually iron,at which time no more energy can be produced and the star collapses. The beginning of a super nova!

Answer 4

Funny high pitched voices in people.

Answer 5

Trouble for the crew of the "Enterprise"!

Answer 6

Answer is A.