Cooking an egg, Baking bread, and Converting frost to water vapor (melting, boiling, and evaporation, generally) are endothermic processes. Why they are endothermic?
The correct answer and explanation is:
Correct Answer:
Cooking an egg, baking bread, and converting frost to water vapor are endothermic processes because they all absorb heat energy from their surroundings to proceed.
Explanation (300 words):
An endothermic process is any physical or chemical change that requires the input of heat energy to occur. In other words, the system absorbs energy from the surroundings to make the change happen. Cooking an egg is an example of an endothermic chemical process. When an egg is heated, the proteins inside unfold and form new bonds in a process called denaturation and coagulation. This transformation requires energy to break the original bonds in the raw egg white and yolk proteins before they can form new structures. This energy comes from the heat applied during cooking.
Baking bread is another example of an endothermic process. The heat supplied by the oven is absorbed by the dough. This heat activates the yeast or other leavening agents, causing fermentation or chemical reactions that produce gas and expand the dough. Heat also enables starches and proteins in the flour to gelatinize and form a firm structure. Without constant heat input, these chemical changes would not occur, and the bread would remain raw dough.
Converting frost to water vapor involves two physical changes that both require energy input. First, frost melts from solid ice to liquid water. This melting process absorbs heat called the heat of fusion. Then, for water to change from liquid to gas, it must absorb even more heat, known as the heat of vaporization. In some cases, frost can change directly from solid to gas through sublimation, which also absorbs energy. All these phase changes require heat because the molecules must overcome intermolecular forces holding them in solid or liquid form.
In summary, cooking an egg, baking bread, and converting frost to water vapor are endothermic because they cannot occur unless energy is absorbed from the surroundings to break bonds or overcome forces within the material.