Final answer:
The correct statements about the universe include that it is expanding, heavy elements are relatively rare, visible matter is primarily hydrogen and helium, and there is evidence for a finite age of 13.8 billion years. There is no support for the universe having a definite edge or a single center.
Step-by-step explanation:
Based on the information provided from the introduction to the universe, several correct statements about the universe can be identified:
- The universe is expanding. This has been observed through measurements of the rate of expansion from nearby galaxies.
- Heavy elements are relatively rare in the universe. Most of the early universe consisted of hydrogen and helium, plus a small amount of lithium. Heavier elements came into existence later within stars.
- The visible matter in the universe is mostly hydrogen and helium. This is based on the abundances of these elements observed in stars and galaxies.
- There is evidence that the universe is not infinitely old. Observations suggest that the universe started expanding about 13.8 billion years ago.
However, the other statements mentioned are not supported by current astronomical evidence:
- The universe does not have a definite edge; it is homogeneous and isotropic on large scales.
- The universe does not have a single center; the expansion of the universe happens uniformly throughout all space.