Which term describes a change in a substance that does not involve a change in the identity of the substance?

Which term describes a change in a substance that does not involve a change in the identity of the substance?

• A. Chemical change
• B. Energy change
• C. Physical change
• D. Nuclear change

Answer: (C)

Physical change means the substance changes form or state without changing its chemical identity. The molecules stay the same, so you still have the same substance at the end—just in a different form or amount. Examples include ice melting to water, water boiling to steam, or a metal being bent. Energy can be involved (heating or cooling), but no new substances are created. In contrast, a chemical change creates new substances with different properties (like rust forming from iron and oxygen). Nuclear changes alter the atomic nucleus. So the term that fits is physical change.

Physical change means the substance changes form or state without changing its chemical identity. The molecules stay the same, so you still have the same substance at the end—just in a different form or amount. Examples include ice melting to water, water boiling to steam, or a metal being bent. Energy can be involved (heating or cooling), but no new substances are created. In contrast, a chemical change creates new substances with different properties (like rust forming from iron and oxygen). Nuclear changes alter the atomic nucleus. So the term that fits is physical change.