Which statement about heat transfer by radiation is true?

Which statement about heat transfer by radiation is true?

• A. It can occur through vacuum
• B. It requires contact
• C. It requires a circulating fluid
• D. It only occurs in solids

Answer: (A)

Radiation transfers heat by electromagnetic waves, so it doesn’t need any particles to move the energy. That’s why it can travel through empty space—the heat from the Sun reaches Earth through the vacuum of space. Because radiation doesn’t rely on contact or a surrounding fluid, it can move from a hot object to another object or into space without touching or circulating anything. This also means it isn’t limited to solids—hot surfaces can emit radiant energy that warms liquids and gases too. So the statement that heat transfer by radiation can occur through vacuum is the true description.

Radiation transfers heat by electromagnetic waves, so it doesn’t need any particles to move the energy. That’s why it can travel through empty space—the heat from the Sun reaches Earth through the vacuum of space.

Because radiation doesn’t rely on contact or a surrounding fluid, it can move from a hot object to another object or into space without touching or circulating anything. This also means it isn’t limited to solids—hot surfaces can emit radiant energy that warms liquids and gases too.

So the statement that heat transfer by radiation can occur through vacuum is the true description.