Boiling Point is defined as which of the following?

Boiling Point is defined as which of the following?

• A. the boiling point of a liquid at a pressure of 14.7 psi
• B. when liquid turns to vapor
• C. the density of the liquid
• D. the viscosity of the liquid

Answer: (B)

Boiling point is the temperature at which a liquid changes into vapor. This is the moment when the liquid’s vapor pressure matches the surrounding pressure, allowing bubbles to form throughout the liquid and rise to the surface. That observable change—liquid turning into vapor—is why the correct choice best describes boiling point. The other options refer to properties like density or viscosity, which do not define the boiling process, or pin the definition to a specific pressure rather than the phase transition itself. Remember: boiling point depends on pressure, but the defining idea is the transition from liquid to vapor.

Boiling point is the temperature at which a liquid changes into vapor. This is the moment when the liquid’s vapor pressure matches the surrounding pressure, allowing bubbles to form throughout the liquid and rise to the surface. That observable change—liquid turning into vapor—is why the correct choice best describes boiling point. The other options refer to properties like density or viscosity, which do not define the boiling process, or pin the definition to a specific pressure rather than the phase transition itself. Remember: boiling point depends on pressure, but the defining idea is the transition from liquid to vapor.