🔍 Key Concepts

• Modes of heat transfer: how energy moves in conduction, convection, and radiation • Role of a material medium: which methods need a solid, liquid, or gas to carry the heat, and which one can occur through empty space • Infrared electromagnetic waves: how heat from the sun reaches the Earth

💭 Think About

• Which heat transfer method can occur even in a vacuum, where there is no material medium at all? • In which process does heat move by direct contact between molecules, and in which by movement of fluids like air or water? • Think about standing near a fire: which type of heat transfer lets you feel the warmth even if the air is still and you’re not touching anything hot?

✅ Before You Answer

• Identify which options are not actually modes of heat transfer in thermodynamics. • Eliminate any methods that require physical contact or bulk fluid motion to move heat. • Match the phrase “electro-magnetic energy in the infrared spectrum” with the correct heat transfer mechanism.