3. compare the words accurate and precise. which do you think is more important?

Accuracy is when the observations are closest to the actual value, while precise isn't necessarily close to the actual value, but different observations are close to each other.

E.G

Accuracy: Getting the bullseye each time.

Precise: Darts landing on the same part of the board everytime.

Accuracy is the most important though, since the actual value is more valuable than values that just so happen to be close together.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.