Molten (liquid) steel and solid steel are different because of which property?

• A. The chemical composition of the steel
• B. The type of atoms present in the steel
• C. The number of protons in iron atoms
• D. The arrangement and movement of particles

Answer: (D)

Verified step by step guidance

1. Understand that the difference between molten (liquid) steel and solid steel is related to the physical state of the material, not its chemical composition or atomic identity.
2. Recall that chemical composition refers to the types and amounts of elements present, which remain the same in both molten and solid steel.
3. Recognize that the number of protons in iron atoms defines the element iron itself and does not change between solid and liquid states.
4. Focus on the arrangement and movement of particles: in solid steel, atoms are arranged in a fixed, orderly pattern and vibrate in place, while in molten steel, atoms have more freedom to move and are not fixed in a rigid structure.
5. Conclude that the key difference lies in the physical arrangement and mobility of atoms, which changes when steel transitions from solid to liquid.