A 100.-mL sample of water is taken from the Pacific Ocean, and the water is allowed to evaporate. The salts that remain (mostly NaCl) have a mass of 3.85 g. Calculate the original concentration of NaCl, in g per liter, in the water sample.

i believe it is 40–40–20%

explanation:

that's what i got you can count the number of atoms

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.