I think answer is
C. Something that can be observed or measured while changing the identity of the substance
Answer:
5 , I think. sorry if its wrong
<span>Carbon must share 4 electrons total with the the two Oxygen atoms in order to fill it's outer electron shell, and each Oxygen atom must share 2 electrons with the Carbon atom to fill their electron shells. Therefore, in total 8 electrons must be shared (4+2+2=8)</span>