Question

define one atmosphere

Answer 1

The blanket of gas on the surface of a planet or satellite. Note: The atmosphere of the Earth is roughly eighty percent nitrogen and twenty percent oxygen, with traces of other gases

One standard atmosphere, which is also referred to as one atmosphere, is equivalent to 101,325 pascals, or newtons of force per square metre (approximately 14.7 pounds per square inch)

Answer 2

The standard atmosphere (symbol: atm) is a unit of pressure defined as 101325 Pa (1.01325 bar). It is sometimes used as a reference or standard pressure.