Question

set 1 - generalized nucleosynthesis in a massive star
elements in the star
chemical symbol name
h hydrogen
he helium
c carbon
o oxygen
ne neon
mg magnesium
si silicon
s sulfur
fe iron
key
combines to form

1. which statement is true about the process of nucleosynthesis?

(1) nucleosynthesis occurs immediately when a star is born, forming all the elements shown in the model.
(2) nucleosynthesis occurs continuously in all stars, forming all the elements shown in the model.
(3) nucleosynthesis occurs continuously in all stars, but only massive stars form the core elements in the last stage of the stars’ life.
(4) nucleosynthesis occurs only seconds before a star explodes to become a supernova (explodes).

Explanation:

Nucleosynthesis is the process of creating new atomic nuclei from pre - existing nucleons (protons and neutrons). In all stars, hydrogen fuses into helium through nuclear fusion continuously. However, the formation of heavier elements like carbon, oxygen, and iron occurs mainly in massive stars during the later stages of their lives. Smaller stars do not have enough mass and temperature to produce these heavier elements.

Answer:

(3) Nucleosynthesis occurs continuously in all stars, but only massive stars form the core elements in the last stage of the stars’ life.