[AdP13]

Hi, I'm a 16 y/o currently studying the topic of Exothermic and Endothermic reactions.
I was wondering about the definition of an Endothermic reaction: a reaction that absorbs energy from the surroundings, including heat energy, such that there is a decrease in temperature. I know there is an explanation for this but i do not understand. If it absorbs heat, how does it result in a cooler temperature than its surroundings? Should it not increase in temperature after absorbing heat?
I greatly appreciate a response.

[chenbeier]

No, if a reaction takes place which endothermic, then it needs energy. Energy can flow only from a higher level to a lower one, what means the surrounding must be warmer or the surroundings will cool down.
If it is exothermic then its reverse. Heat will be released the surrounding will get warmer.

[Borek]

It absorbs energy in form of chemical bonds - so in a way this energy is "lost" from the point of view of the system temperature. That's why it gets colder instead of heating up.