At what temperature does water boil at standard atmospheric pressure?

Water boils at 100°C at standard atmospheric pressure, which is defined as the pressure of 1 atmosphere (101.3 kPa or 760 mmHg). At this temperature, the vapor pressure of the water equals the atmospheric pressure, allowing bubbles of water vapor to form throughout the liquid, leading to boiling.

This temperature is a fundamental reference point in thermodynamics and is particularly significant in chemistry and other sciences. Understanding this boiling point is crucial because it serves as a baseline for studying the properties of other liquids and the effects of pressure on boiling points. For instance, at higher pressures, the boiling point of water increases, whereas, at lower pressures, it decreases.

The other temperatures provided do not reflect the boiling point of water under standard atmospheric conditions. For example, boiling at 90°C, 95°C, or 105°C does not correspond with the standard atmospheric pressure, indicating that those scenarios would involve either different pressures or substances that do not adhere to water's boiling point characteristics at normal atmospheric conditions.