Two friends are discussing physical and chemical changes. Isabela says that when you eat, it is a physical change because when you chew, the food is only changed into smaller pieces. Mirabel says that when you eat, it is a chemical change because your body digests the food as the chemicals in your body break down the food into energy. Who is right?
Both are right if you separate the problem.
Isabella is correct that chewing the food is a physical change. After it is chewed and swallowed then the digestive juices start flowing and the chemical process starts so that part is a chemical change. Technically, the chemical process starts as soon as the food is chewed into smaller pieces but the major digestion starts after swallowing the food.
Both Isabela and Mirabel are partially correct. Eating involves both physical and chemical changes.
Isabela is right in saying that chewing is a physical change. When you chew food, it is broken down into smaller pieces, but the composition and chemical makeup of the food remains the same. So, chewing represents a physical change because it only affects the size and shape of the food.
Mirabel is also correct in stating that digestion involves chemical changes. Once you swallow the food, it enters your digestive system, where enzymes and acids break down the complex molecules in the food into simpler substances such as carbohydrates, proteins, and fats. These simpler substances are absorbed into the bloodstream and used by the body for energy, growth, and various bodily functions. Therefore, digestion represents a chemical change because the food is chemically transformed into different substances in order to be utilized by the body.
In conclusion, both physical (chewing) and chemical (digestion) changes occur when you eat.