Question

Which of the following is an indication of a chemical reaction?

Ofreezing
O melting
O release of heat
O all of the above

Answer 1

• Release of heat.

Step-by-step explanation:

• In exothermic chemical reactions, heat is released due to multiple collisions of the reactant molecules.

→ Freezing and melting are physical changes.

• Other physical changes are;

• sublimation
• condensation
• evaporation

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