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Air pollution is the introduction of airborne chemicals, particulate matter or biological materials that cause harm or discomfort to organisms. [59] The population growth , industrialization and motorization of human societies have significantly increased the amount of airborne pollutants in the Earth's atmosphere, causing noticeable problems ...
The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. [2] Most organisms use oxygen for respiration ; lightning and bacteria perform nitrogen fixation which produces ammonia that is used to make nucleotides and amino acids ; plants , algae , and cyanobacteria use carbon ...
Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, [13] Henry Cavendish, [14] and Joseph Priestley, [15] who referred to it as burnt air or phlogisticated air. French chemist Antoine Lavoisier referred to nitrogen gas as "mephitic air" or azote, from the Greek word άζωτικός (azotikos), "no life", due to it being ...
The order of elements by volume fraction (which is approximately molecular mole fraction) in the atmosphere is nitrogen (78.1%), oxygen (20.9%), [20] argon (0.96%), followed by (in uncertain order) carbon and hydrogen because water vapor and carbon dioxide, which represent most of these two elements in the air, are variable components. Sulfur ...
There are many different sources of air pollution. Some air pollutants (such as nitrogen oxides) originate mainly from human activities, [39] while some (notably radon gas) come mostly from natural sources. [40] However, many air pollutants (including dust and sulfur dioxide) come from a mixture of natural and human sources. [41]
A breathing gas is a mixture of gaseous chemical elements and compounds used for respiration. Air is the most common and only natural breathing gas. Other mixtures of gases, or pure oxygen, are also used in breathing equipment and enclosed habitats such as scuba equipment, surface supplied diving equipment, recompression chambers, high-altitude mountaineering, high-flying aircraft, submarines ...
It is composed mostly of iron ... forming the primarily nitrogen–oxygen atmosphere of ... the mean annual air temperature at sea level decreases by about 0.4 ...
Atmospheric chemistry is a branch of atmospheric science that studies the chemistry of the Earth's atmosphere and that of other planets. This multidisciplinary approach of research draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology, climatology and other disciplines to understand both natural and human-induced changes in atmospheric ...