Which statement about the physical change of liquid water boiling into steam is true?

• A. Boiling water produces hydrogen and oxygen gases.
• B. No new substances are formed during the boiling of water.
• C. Boiling water is an example of a chemical change.
• D. The chemical composition of water changes when it boils.

Answer: (B)

Verified step by step guidance

1. Understand the difference between physical and chemical changes: A physical change affects the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances with different chemical properties.
2. Identify what happens when liquid water boils: Boiling is the process where liquid water changes to water vapor (steam), which is a change in the state of matter from liquid to gas.
3. Recognize that during boiling, the molecules of water (H\_2O) remain chemically the same; only their physical state changes, so no new substances are formed.
4. Evaluate the given statements: Boiling water does not produce hydrogen and oxygen gases separately, it is not a chemical change, and the chemical composition of water does not change during boiling.
5. Conclude that the true statement is: 'No new substances are formed during the boiling of water,' because boiling is a physical change involving a phase transition.