Endothermic and Exothermic reactions, Thermal energy

I was watching some youtube videos about heating, and somehow got the point of exothermic and endothermic reactions, I know that negative energy change in a reaction means the reaction is exothermic, and that a positive is endothermic, but what I do not understand is, if internal energy means the sum of the average kinetic energy of the particles + the potential energy between their bonds, if an endothermic reaction means it's taking in heat from the surrounding, and making bonds, doesn't making bonds take energy and therefore would mean it's losing energy, and if it's taking in heat from the surrounding, how is it getting colder when it would make more sense (to me) for it to get hotter, sorry if this is a dumb question but I seem to struggle to understand it, also feel free to correct any mistakes I've made in my statements as I'm not 100% on all of this.

Reply 1

Pigster

Original post by Luttece

doesn't making bonds take energy and therefore would mean it's losing energy

Making bonds releases energy!

BUT, before you can make bonds, you must break the bonds in the reactants, which means energy goes in initially.

To determine if a reaction is exo or endothermic, you compare the amount of energy you initially put in to break bond to the amount you get back out when you form the new bonds.

If more is taken in than is given out, the reaction overall will be endothermic.