Molten steel, melted steel, liquid steel, and solid steel are different because of which property?

• A. Their atomic number
• B. Their chemical composition changes
• C. The presence of impurities
• D. Their physical state due to temperature changes

Answer: (D)

Verified step by step guidance

1. Understand that the terms molten steel, melted steel, liquid steel, and solid steel refer to the same material (steel) but in different physical states.
2. Recall that the atomic number of an element is a fixed property and does not change with physical state or temperature.
3. Recognize that the chemical composition of steel remains constant during melting or solidification; no new elements are added or removed in this process.
4. Consider that impurities may affect properties but are not the defining factor for the difference between molten and solid steel in this context.
5. Conclude that the key difference among these terms is the physical state of steel, which changes due to temperature variations (solid at lower temperatures, liquid when heated above melting point).