Question

explain how the composition of a star that will form a billon years in the future will differ the composition of our sun.

Answer 1

Step-by-step explanation:

Basically the star slowly burns its hydrogen into Helium. Depending on the mass, the star will have a turbulent core where the Helium will be fully mixed or a radiative core where the helium will settle at the centre (remember it's heavier than Hydrogen). The second case is what happens in the Sun.