Question

Which of the following are physical changes and which are chemical changes? Rotting Food Fermenting Charcoal Burns in a Grill Decaying Plant Cutting Vegetables Melting Butter

Answer 1

Physical changes: Cutting vegetables and melting butter.

Chemical changes: Rotting food, fermenting, charcoal burning in a grill, and plant decaying.

Explanation:

• Rotting food: This would be a chemical change, because it's not reversible and involves changing the bonds of chemicals in the food. The resulting rotten food is chemically different than the initial, non-rotten food.
• Fermenting: This is when microorganisms like yeast break down molecules like glucose—which is a chemical change, because glucose is being chemically altered.
• Charcoal burning in a grill: Most times, when something is burning, it is a chemical change. Here, charcoal burning in a grill would be a combustion reaction which produces carbon dioxide and water.
• Decaying plant: Another chemical reaction, because this reaction is non-reversible. Also because the decomposition of the plant changes the chemical formulas of the compounds in the plant.
• Cutting vegetables: Physical, because no bonds are being formed or broken. Only the shape of the substance is changed.
• Melting butter: Physical. Butter is changing from a solid to a liquid here, but it's still butter—this means that no chemical changes are happening.