What is the atmospheric pressure (psia) of air on the surface of earth at sea level?

The atmospheric pressure at sea level is defined as the pressure exerted by the weight of the atmosphere. This pressure is commonly recognized to be approximately 14.7 pounds per square inch absolute (psia). This value is established at standard atmospheric conditions, which include a temperature of 15°C (59°F) and a relative humidity of 0% at sea level.

Understanding this value is crucial for various applications, such as calculating gas pressures in systems, regulating combustion processes, and ensuring safe operation in heating and ventilation systems.

The other values listed in the options do not reflect the standard atmospheric pressure. They may represent specific conditions or processes but are not recognized as the standard atmospheric pressure at sea level. This makes 14.7 psia the correct and widely accepted answer in both scientific and engineering contexts.