Answer: 3.solidification of volcanic lava
Explanation: Exothermic reactions are those in which energy is released by the system and endothermic reactions are those in which energy is absorbed by the system.
Evaporation of alcohol requires energy to convert liquid state to gaseous state and thus is endothermic.
Sublimation of iodine requires energy to convert solid state to gaseous state and thus is endothermic.
Solidification of solid lava releases energy as liquid state is being converted to solid state and thus is exothermic.
Burning of paper requires energy and thus is endothermic.
