Convection carries heat to the thermometer. Radiant energy warms the thermometer. Mechanical energy from the flame carries heat to the thermometer. Heat from the flame is conducted through the metal rod to the thermometer.
I gave my students this multiple choice question: One end of a metal rod is placed over a flame during an investigation. A thermometer is touching the opposite end of the metal rod. Which best describes what is happening during this investigation?

Only one answer is correct among these 4 choices:
- Convection carries heat to the thermometer.
- Radiant energy warms the thermometer.
- Mechanical energy from the flame carries heat to the thermometer.
- Heat from the flame is conducted through the metal rod to the thermometer.

Could you tell me which one is correct?

Heat from the flame is conducted through the metal rod to the thermometer.