Why didn't elements heavier than helium form in the first minutes of creation?
A) The first generation of stars used them up too quickly to observe them.
B) There was not enough matter in the universe at that time.
C) When He-4 was formed, the expansion cooled the cosmos below 100 million K.
D) The electrons slowed down enough to be captured into orbits by protons.
E) Only Type I supernovae can produce iron and heavier elements.

Question

Quizplus · Accepted Answer

The high temperatures in the early universe would have allowed for the fusion of protons and neutrons into heavier elements, but the expansion of the universe caused it to cool down rapidly, preventing the formation of elements heavier than helium. When helium-4 was formed, the expansion cooled the cosmos below 100 million K, halting further fusion reactions.

Why Didn't Elements Heavier Than Helium Form in the First