Question

Nucleosynthesis is the process in which nuclei fuse together to form different elements. The table summarizes nucleosynthesis in stars.

Life Stage Main Nucleosynthesis Process
main sequence Hydrogen is fused into helium.
giant or supergiant A smaller star fuses helium into carbon and oxygen. A massive star also fuses heavier elements up to iron.
death The core of a smaller star contracts into a white dwarf. A massive star contracts and then explodes into a supernova that creates elements heavier than iron.

What conclusion can be made from the table?
A.
Nucleosynthesis produces less energy in smaller and younger stars.
B.
Nucleosynthesis creates all elements on the periodic table by the time a star dies.
C.
Nucleosynthesis speeds up over time as stars progress through their stages.
D.
Nucleosynthesis varies based on the mass and stage of the star.

Answer 1

D. Nucleosynthesis varies based on the mass and stage of the star.

The table shows different fusion products for main-sequence vs giant/supergiant stages and different outcomes for smaller versus massive stars (massive stars fuse heavier elements up to iron and supernovae make elements heavier than iron).