🔍 Key Concepts

• energy cannot be created or destroyed, only changed in form • difference between conservation and conversion • how the idea of "in equals out" relates to a closed system

💭 Think About

• Which option describes a situation where the total amount stays the same, even if it changes form? • Which words in the options suggest a change in type (turning one thing into another) rather than keeping the total the same? • In physics, which basic principle is often summarized as "you can’t get more out than you put in"?

✅ Before You Answer

• Look for the choice that refers to keeping the total energy constant, not changing one substance into another • Eliminate any options that talk about matter turning into energy or energy turning into matter • Confirm that the word you choose matches how physics textbooks describe the basic energy bookkeeping rule: in a closed system, total energy stays the same