1. endothermic reactions involve absorption oof energy from the surroundings
2. exothermic reactions release energy to its surroundings
3. If the reaction flask feels warm, that is the result of an exothermic reaction because there was energy produced from the reaction that caused the reaction flask to gain thermal energy. This thermal energy would cause the flask to feel warm.
4. If the reaction shows a drop in temperature, it is the result of an endothermic reaction because energy was absorbed from the surroundings. Temperature is the measure of average kinetic energy, meaning when the amount of energy decreases, the temperature will also decrease.