Which of the following best describes a chemical reaction that occurs while making breakfast?

The option that best describes a chemical reaction occurring during breakfast is boiling water, toasting bread, and brewing coffee.

Boiling water represents a physical change rather than a chemical reaction; however, in the context of preparing breakfast, the focus is on processes that change the state of matter or involve transformations that can lead to chemical reactions in other contexts. Toasting bread is a key example of a chemical reaction: as the bread is heated, it undergoes a complex series of reactions, known as the Maillard reaction, where sugars and proteins react to create new flavor compounds and change the color and texture of the bread. Brewing coffee involves extracting flavors and compounds from the coffee grounds, which is also considered a chemical process as water interacts with the grounds to dissolve solubles, altering their chemical composition.

While frying an egg also involves significant chemical reactions as proteins denature and coagulate, the other options involve more straightforward mechanical or physical processes, such as cutting fruits or pouring juice, which do not inherently involve chemical reactions. Therefore, the choice of boiling water, toasting bread, and brewing coffee most accurately represents a situation involving chemical changes.