Burning Candle: Combustion and Mass Conservation

Steps:

• Observe the diagram of the burning candle, noting wax melting and flame.
• Identify the process as combustion, where wax reacts with oxygen.
• Apply law of conservation of mass: total mass remains constant despite gas products.
• Compare options to determine which illustrates mass balance correctly.

Why A is correct:

• Option A shows equal mass before and after burning, aligning with the law of conservation of mass in closed systems.

Why the others are wrong:

• B incorrectly depicts mass loss due to burning, ignoring gaseous products.
• C suggests mass gain from air, violating conservation principles.
• D focuses on energy release, not addressing the mass query.

Not enough information on exact diagram details, but A fits standard candle combustion analysis.

Final answer: A