Answer: To show the number of atoms present.
Explanation: As in CO² (Carbon dioxide), there is a small 2 next to the symbol "O" (oxygen) to explain that there are two oxygen atoms.
Yes, especially if its from a lake, pond, or ocean since water moves around. Dinasours could have spit out or maybe dripped some water, so basically yes.
Gravity pulling the mass of the atmosphere toward the center of the
earth. Atmosphere includes air, water vapor, etc.
Mixture/ compound
hope this helps
