Question

Which of the following gives the two main assumptions of theoretical models of galaxy evolution?

A) The beginning of the universe is modeled after a supernova explosion, and all the elements were produced in the proper quantities by the star.
B) Hydrogen and helium filled all of space, and certain regions of the universe were slightly denser than others.
C) Hydrogen and helium filled all of space, and all the universe was exactly the same density.
D) The universe has always been expanding, and denser areas contracted to form the first stars.
E) The universe was composed originally only of hydrogen, and all the other elements came from stars

Answer 1

The two main assumptions of theoretical models of galaxy evolution are that hydrogen and helium filled all of space, and certain regions of the universe were slightly denser than others. Additionally, the assumption is that the universe has always been expanding, and denser areas contracted to form the first stars.

Step-by-step explanation:

The two main assumptions of theoretical models of galaxy evolution are that:

1. Hydrogen and helium filled all of space, and certain regions of the universe were slightly denser than others.
2. The universe has always been expanding, and denser areas contracted to form the first stars.

These assumptions provide the basis for understanding how galaxies form and evolve over time.