Question

a cold pack is snapped, and the chemical reaction causes the pack to feel cold. which kind of reaction is this? (1 point)

this is an exothermic reaction because the surroundings took energy from the system.

this is an endothermic reaction because the system took energy from the surroundings.

this is an endothermic reaction because the surroundings took energy from the system.

this is an exothermic reaction because the system took energy from the surroundings.

Explanation:

Endothermic reactions absorb energy from the surroundings, which makes the surroundings feel cooler. When the cold pack is snapped, the chemical reaction in the pack (the system) takes in thermal energy from the surrounding area (including the user's hand), causing the pack to feel cold. Exothermic reactions release energy, which would make the pack feel warm, so the other options misclassify the reaction or describe the energy flow incorrectly.

Answer:

This is an endothermic reaction because the system took energy from the surroundings.