It is twice as large. It contains more electrons. It stores more chemical energy. It destroys less energy when used.
I gave my students this multiple choice question: A new battery claims that it "lasts twice as long as competing batteries under the same loading conditions." Which comparison of the battery with competing batteries would validate this claim?

Only one answer is correct among these 4 choices:
- It is twice as large.
- It contains more electrons.
- It stores more chemical energy.
- It destroys less energy when used.

Could you tell me which one is correct?

It stores more chemical energy.