Final answer:
An explosion resulting from the reaction of Methane (CH₄) and Oxygen (O₂) constitutes a chemical change, as new substances are formed and chemical bonds are broken and made.
Step-by-step explanation:
Chemical Change Due to Reaction of Methane and Oxygen
When Methane (CH₄) and Oxygen (O₂) react to cause an explosion, it indicates a chemical change. This is because the reaction involves the breaking and forming of chemical bonds, which results in the creation of new substances with different physical and chemical properties: carbon dioxide (CO₂) and water (H₂O). As chemical changes are often not easily reversed, the transformation that occurs upon the ignition of methane and oxygen, which releases heat and leads to an explosive reaction, is characteristic of a chemical change. Given the options A) Physical change, B) Chemical change, C) Thermodynamic change, and D) State change, the correct answer is B) Chemical change.