Franklin D. Roosevelt's famous saying from the beginning of his
Presidency

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.

answer: option (a) is the correct answer.

explanation:

the measurement of hydrogen ions in a solution is known as ph.

if ph of a solution is less than 7 then the solution is acidic. if ph of a solution is greater than 7 then the solution is basic.

when the ph of a solution equals 7, then the solution is considered as neutral.

the ph of pure water is 7, therefore, it means that concentration of hydronium ions equals that of hydroxide ions.