Which of the following is best described as being made of matter?

• A. Heat energy
• B. A beam of light
• C. Sound waves
• D. A block of iron

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the definition of matter. Matter is anything that has mass and occupies space (has volume).
2. Step 2: Analyze each option to see if it has mass and occupies space. Heat energy is a form of energy, not matter, so it does not have mass or volume.
3. Step 3: A beam of light is electromagnetic radiation, which has no mass and does not occupy space, so it is not matter.
4. Step 4: Sound waves are mechanical waves that travel through a medium, but the waves themselves are energy disturbances, not matter.
5. Step 5: A block of iron is a solid object with definite mass and volume, so it fits the definition of matter perfectly.