If a heavy atom falls into a star will it break into neutrons and protons?

[supernovasunrise]

I've been wondering about this for awhile - if a 'heavy' atom consisting of a nucleus with many protons and neutrons  such a lithium or another such atom - will it break apart into neutrons and protons in a star? Would the neutrons themselves degrade? I seem to remember reading that there are heavier elements present in a star's 'atmosphere' such as oxygen  or carbon. But will they not drift gradually to the star's core and be separated into their constituent subatomic parts? I mean stars in the main part of their lifecycle - not at the nova or supernova stages.

[Knight of Clear Skies]

Welcome to the forum. Many heavy atomic nuclei are very stable, iron being the most stable of all, and could plausibly survive falling into a star. It would depend on the speed of the collision. Lithium is particularly unstable and is destroyed at a 'mere' million degrees C or so. Most stars destroy lithium readily, it can survive at the surface but not if convection takes it down near the core.

On the other hand, an atom impacting a neutron star will be broken down into its sub-atomic constituents. The escape velocity of a neutron star is 1/3 to 1/2 the speed of light, so anything falling from a distance will hit at least this speed.

[ronin]

It would makes sense that they are not broken down into their constituent parts. Otherwise any atom in the core would be broken down back to protons and neutrons and then take part in the fusion cycle again. Which means perpetual "motion" and a violantion of the laws of thermo dynamics.

As Neitrons are unstable and break to a Proton and electron  you would seem to have H > Heavy Element > H > Heavy element > H > Heavy Element > H ....... An unending cycle.

Some through collisions etc will go through a fission process, just the amount will be small. It will be a situation of some fission as that is in a way actually part of the PP1 process for fusion. If I recall the final stage is 2H3 (tritrium) -> He +2N, the explusion/splitting of the 2N being fission not fusion.

Additionally the big stars and even ours to an extent will form shells of heavier elements and they remain as the element. They do not flash into existance at the end of the stars dying seconds.

[Stu]

You might find this book an interesting read?

https://www.amazon.co.uk/Magic-Furnace-Search-Origins-Atoms/dp/0099578018#productDescription_secondary_view_div_1500195157108