Science
Energy
Conceptual
11–12 yrs
Energy can't be created or destroyed
能量守恒定律
Description
Explain the principle of conservation of energy (energy cannot be created or destroyed, only transferred between stores), and describe how energy is dissipated as thermal energy to the surroundings in all real processes
Mastery Evidence
- States the law of conservation of energy
- Explains why the total energy in a closed system is always the same even though it changes form
- Explains what dissipation means and why it happens in real machines (friction, air resistance)
- Gives an example showing why 'wasted' energy is not lost but transferred to the surroundings
Assessment Prompt
If your child charged their phone overnight and was asked where the electrical energy goes, could they explain what conservation of energy means — and why the charger gets warm even though that heat isn’t doing any useful work?
