Which indicator most likely suggests that a chemical change is taking place?

• A. Formation of a precipitate
• B. Dissolving of a solute in a solvent
• C. Change in physical state from solid to liquid
• D. Change in size or shape

Answer: (A)

Verified step by step guidance

1. Understand the difference between physical and chemical changes. A physical change affects the form of a substance but not its chemical composition, while a chemical change results in the formation of one or more new substances with different properties.
2. Analyze each option to determine if it indicates a chemical or physical change:
3. - Dissolving of a solute in a solvent is a physical change because the solute molecules disperse but do not chemically react.
4. - Change in physical state from solid to liquid is a physical change involving a phase transition without altering chemical identity.
5. - Change in size or shape is a physical change as it only affects the form, not the substance itself.
6. - Formation of a precipitate indicates a chemical change because it involves the creation of a new solid substance from a solution, showing a chemical reaction has occurred.