Sun's Life-cycle Questions

[Z07]

What I know:

 

Nothing.

 

What I suspect:

 

The Sun is busy making helium by fusing hydrogen.

 

Question 1: Is the hydrogen in the Sun mostly protium?

Question 2: Which isotope of helium is most often created by the Sun? Q2A: Are neutrons being created?

 

The mass of the produced helium is less than the mass of the hydrogen that went into its creation. Therefore, the Sun's total mass decreases over time as hydrogen is fused into helium.

 

The average diameter of the Sun is a reflection of the balance between the gravitational attraction and the explosive force of the energy released from fusion. In absence of fusion, gravity would compress the Sun into a much smaller sphere. In absence of gravity, the fusion would blast the Sun into a thin cloud of expanding gas.

 

It seems to me that the Sun should be growing in size as it loses mass.

 

Question 3: Is the Sun growing in size?

 

When the Sun's hydrogen is all consumed, the Sun will then begin fusing helium into carbon. The carbon will have less mass than the helium that went into its creation. The Sun will again lose mass and grow in size.

 

Question 4: As the Sun enters the red giant phase of its life, will it grow smoothly to its new size as its mass decreases or will it be more like flipping a switch? (This sudden expansion is what is depicted in graphics shown on some TV "science" shows and it didn't seem right to me that the change could be so sudden.)

 

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Question X: What happens to the relatively small amount of heavy elements that the Sun has captured since its formation? If you could freeze time and look into the core of the Sun would you see its collection of heavy elements in some molten pool? plasma? gaseous state? Just what happens to a mostly iron meteoroid that falls into the Sun's gravity well?

Edited September 3, 2013 by Z07

[mathematic]

http://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_reaction

 

The above will tell you everything about the first two questions. Short answer H1 -> He4, no free neutrons.

 

I believe the answer to 3 is yes. The red giant growth is fast, but I don't think it will be explosive.