Question

which statement describes what it means for energy to be conserved?
energy gained by a reaction is new energy.
energy released by a reaction disappears.
energy released by a reaction is gained by the surroundings.
energy gained by a reaction must be taken from another reaction.

Explanation:

The law of conservation of energy states that energy cannot be created or destroyed, only transferred or transformed.

• The first option is wrong because energy isn't "new" (energy can't be created).
• The second option is wrong as energy doesn't disappear (can't be destroyed).
• The third option is correct: when a reaction releases energy, that energy is transferred to the surroundings (e.g., heat released into the air, which is the surroundings gaining that energy).
• The fourth option is wrong because energy for a reaction is typically from the system - surroundings interaction or internal energy changes, not necessarily from another reaction.

Answer:

C. Energy released by a reaction is gained by the surroundings.