During an experiment vinegar was added to baking soda. the following observations were recorded. observation 1: the container with the reaction mixture feels cooler. observation 2: gas bubbles are released. based on the observation, justify the type of change (physical or chemical) that took place.

Chemical change.

Explanation:

When vinegar (CH₃COOH) is added to baking sods (NaHCO₃) there is a chemical reaction involved which is neutralization. This reaction produces carbon dioxide which is observed as gas release of gas bubbles.

Simultaneously there is making and breaking of bonds and the energy needed to break the bond is greater than the energy released in making the bond thus the reaction is endothermic which overall decreases the temperature of container. Thus the feel of cooling is also a chemical change.

it's c. elements are placed in rows based on how may valencies electrons have.