The boiling of water and sublimation of iodine crystals are endothermic processes.
Answer: Option B & C
Step-by-step explanation:
Endothermic process are the classifications of chemical reactions where the heat is absorbed by the system from the surroundings. As the matters can exists in three phases like solid, liquid and gases.
The endothermic process occurs by absorption of heat energy by the system. So according to the given options, the boiling of water and iodine crystal sublimation follows endothermic process. In the boiling of water occurs when the water molecules absorb heat from the surrounding and convert to gas phase.
Similarly, the sublimation of iodine crystals also require heat energy from the surrounding to break the bonds of the iodine crystals to sublimate to gas phase. Thus the boiling of water and sublimation of iodine crystals are the examples of endothermic processes.