There is a theory that gravity could pull galaxies back together, causing a reverse big bang.
which observation makes this theory less likely than the idea that the universe may continue to expand?
a.) background radiation is present.
b.) galaxies exist outside of the milky way.
c.) the expansion of the universe is accelerating.
d.) gas giants form farther from the sun, where temperatures are cooler.

C. the expansion of the universe is accelerating

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%