Trace gas the relationship can be used to estimate tropospheric residence-times of gases. Trace gas The most abundant gases in the atmosphere are nitrogen (78.1%), oxygen (20.9%), and argon (0.934%). Combined, oxygen, argon, and nitrogen make up 99.934% of the gases in the atmosphere (not including water vapor). The other gases that are not part of the 99.934% of the atmosphere are called trace gases. The abundance of a trace gas can range from a few parts per trillion (ppt) by volume to several hundred parts per million by volume (ppmv). When a trace gas is added into the atmosphere, that process
Most common words in English about half of all written English. According to a study cited by Robert McCrum in "The Story of English," all of the first hundred of the most common words in English are of Anglo-Saxon origin, except for "people", ultimately from Latin "populus", and "because", in part from Latin "causa". Some lists of common words distinguish between word forms, while others rank all forms of a word as a single lexeme (the form of the word as it would appear in a dictionary). For example, the lexeme "be" (as in "to be") comprises all its conjugations ("is", "was", "are", "were", etc.),