Endothermic absorb energy... How do they begin in the first place?? PLEASE, BEFORE ANSWERING I would like you to hear me out. >>> Im really confused as to the phenomenon of why endothermic reactions between mixing of two substances just spontaneously happen.. giving them temporary "cold" properties... Thermal neutrality and the urge for everything to equalize in temperature is completely intuitive to me, so when i think of something getting hot, obviously energy was introduced to the system... In endothermic reactions however, this is not necessarily the case. Obviously one the reaction happens, it has gone to a state of less energy... It is absorbing the room temperature heat and from your fingers when touching. i understand how putting a source of heat between two substances can cause an endothermic reaction, because your introducing outside energy to start with.. they say when bonds are being broken, it costs energy. But what energy is being displaced to being the endothermic reaction, before it gets real cold.. how do bonds just spontaneously break apart and loose energy when they are mixed like metal in a salt solution for example. Could someone explain this in a precise clear manner, cause i think the hardest part of the question is communicating my misunderstanding, I couldn't get the answer I wanted from my chem teacher, she kept saying entropy causes this, naturally. I know what entropy is, i am still confused, however. Thank you for reading, I would very much appreciate some insight. ammonium nitrate cold packs for example... they just magically get cold. this is my observation so far: these spontaneous endothermic reactions when substances are mixed are because they are at an unstable state? and with the cost of a little bit of (room temperature) heat, they break apart into more stable molecules/atoms? The want to go from unstable to stable at the cost of a tiny bit of heat energy from its surroundings make sense to me, but im not sure..