Use the picture to determine if a chemical reaction has occurred.

Yes, a chemical reaction has occurred. Mixing vinegar (which contains acetic acid) and baking soda (sodium bicarbonate) results in the production of carbon dioxide gas, water, and sodium acetate. This reaction is characterized by fizzing and bubbling due to the release of carbon dioxide.

Use the picture to determine if a chemical reaction has occurred. (Digestion = breaking food down)

While I cannot see the picture you mentioned, I can provide general information based on the concept of digestion.

Yes, a chemical reaction occurs during digestion. The process involves breaking down food into smaller molecules by the action of enzymes and other digestive substances. For example, carbohydrates are broken down into sugars, proteins into amino acids, and fats into fatty acids and glycerol. This process involves chemical changes, demonstrating that a chemical reaction has taken place as the food's structure is altered and its components are transformed into forms that the body can absorb and utilize.

Use the picture to determine if a chemical reaction has occurred. Water boiling

No, a chemical reaction has not occurred during the boiling of water. Boiling water involves a physical change in which liquid water is converted to water vapor (steam) due to the addition of heat. The chemical composition of water (H₂O) remains the same before and after boiling; thus, it is a physical change rather than a chemical reaction.

Use the picture to determine if a chemical reaction has occurred. Baking a cake.

Yes, a chemical reaction has occurred when baking a cake. The process involves mixing ingredients such as flour, sugar, eggs, baking powder (or baking soda), and other components, which then undergo chemical changes as they are heated in the oven.

During baking, several reactions take place, including:

- **Protein denaturation:** Proteins in eggs and flour change structure and contribute to the cake's texture.
- **Starch gelatinization:** Starch absorbs moisture and swells, helping to give the cake structure.
- **Carbon dioxide production:** If leavening agents like baking powder or baking soda are used, carbon dioxide gas is produced, causing the cake to rise.

These changes result in a new substance (the baked cake) with different properties than the original ingredients, indicating that a chemical reaction has occurred.