Which of the following contains matter?
a. gravity
b. force
c. energy
d. atoms

i think i know this but want a second opinion

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