Based on the observed amount of deuterium in the universe, we can conclude that
A) ordinary (baryonic) matter makes 75 percent of the mass of the universe.
B) neutrons outnumber protons 7 to 1 in the universe.
C) most of the deuterium that was created during the era of nucleosynthesis has since been destroyed.
D) the density of ordinary (baryonic) matter is about 4 percent of the critical density.
E) we live in a critical-density universe.

Question

Quizplus · Accepted Answer

The observed amount of deuterium in the universe leads us to conclude that the density of ordinary matter (also known as baryonic matter) is about 4 percent of the critical density. This finding is based on the idea that the amount of deuterium produced during the era of nucleosynthesis is proportional to the density of baryonic matter in the universe. Therefore, the measured amount of deuterium can be used to estimate the density of baryonic matter.

Based on the Observed Amount of Deuterium in the Universe