Hydrochloric acid and sodium hydroxide are mixed together to form salt and water. during the reaction, the temperature of the solution increases. which of these best explains why this is considered to be a chemical change?
a. no energy was destroyed.
b. heat was iven off.
c. it involves liquid.
d. new substances formed.

The best answer among the choices is option D. New substances are being formed will best explain that this process is a chemical change. Although, it cannot be seen directly we knew that an acid and base will undergo neutralization reaction forming a salt and water. The heat given off by the reaction can be a parameter however it does not only happens for reactions. It can also happen when dissolving substances.