Relative atomic mass values of some elements

Relative atomic mass values of some elements 

Air usually contains approx. 1% water vapor by vol. (which corresponds to 40% relative humidity at 20° C) oxygen content is then 20.7% by vol. 

From the point of view of safety, it is important to know whether a gas or vapor is lighter or heavier than air. 

Taking the specific density of air at a given temperature to be 1, the relative density of a gas at the 

This measurement is most often referred to as the relative vapor density in the case of liquids, however, it applies only at temperatures above boiling point. 

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