What process created hydrogen and helium in the early universe?
A. Stellar fusion
B. Big Bang nucleosynthesis
C. Radioactive decay
D. Gravitational collapse
Why is the abundance of hydrogen and helium in the universe evidence for the Big Bang theory?
A. It shows that stars are constantly creating these elements.
B. These elements are too light to form in stars alone.
C. Their ratios match predictions from early universe models.
D. Hydrogen and helium are the only elements in the universe.
When did Big Bang nucleosynthesis occur?
A. Within a few seconds after the Big Bang
B. During the formation of the first stars
C. Billions of years after the Big Bang
D. After galaxies began to form