Endothermic and Exothermic reactions, Thermal energy Watch
doesn't making bonds take energy and therefore would mean it's losing 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.