We subtract the enthalpies of the reactants from that of the products:

Since this is < 0, this is an exothermic reaction.
Question:
What occurs to the atoms of reactants in a chemical reaction?
Answer:
In a chemical reaction, the atoms and molecules that interact with each other are called reactants. ... No new atoms are created, and no atoms are destroyed. In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
Precision relates to how close the answers are to each other, so I’d think it would be D because of the limited range between data points.
Moles Chlorine to grams = 35.453 grams.
moles Chlorine to grams = 70.906 grams.
moles Chlorine to grams = 106.359 grams.
moles Chlorine to grams = 141.812 grams.
moles Chlorine to grams = 177.265 grams.
moles Chlorine to grams = 212.718 grams.
Profundal
profundal zone is the coldest and deepest zone