Question

When determining whether a chemical reaction has taken place, you observe and look for several indicators. Which would be considered an indication that a chemical reaction or chemical change has taken place? A) Solid melts. B) Heat is given off. C) Substance dissolves D) Substance changes shape.

Answer 1

The answer is B.

A cannot be the answer is melting is a physical change. No chemical reaction took place.

B is the answer as it is a EXOTHERMIC REACTION so heat will be given off.

C cannot be the answer as dissolving is basically atoms becoming ions, not a chemical reaction whereby a reactant reacts with another reactant to form a product.

D cannot be the answer. Same reason as for why A is not the answer.

Cheers.