The two subspecialties of astronomy are
a. environmental earth science and environmental chemistry.
b. paleontology and geochemistry.
c. astrophysics and planetary science.
d. climatology and atmospheric chemistry.

The following transition occurs at a molecular level for a substance. what transition corresponds to this change in microscopic structure? the carbon dioxide molecules on the left are in a regular, tightly packed pattern. after heating, it becomes much lower density. a. melting b. boiling c. sublimation d. freezing