Question

quiz:
thermal energy
how does the sun warm the earth?
○ electromagnetism
○ convection
○ conduction
○ radiation

Explanation:

To determine how the sun warms the Earth, we analyze the heat transfer methods:

• Electromagnetism is a broad field, not a heat - transfer method for this context.
• Convection needs a fluid (liquid or gas) medium to transfer heat. As there is a vacuum between the sun and the Earth, convection is impossible.
• Conduction requires direct contact between substances. Since the sun and the Earth are not in direct contact, conduction is not the way.
• Radiation is the transfer of heat in the form of electromagnetic waves. The sun emits thermal energy as electromagnetic waves, and these waves can travel through the vacuum of space to reach the Earth and warm it.

Answer:

radiation (the option corresponding to "radiation")