Air is one of the four classical elements – air, water, earth, and fire
Air is the Earth's atmosphere. Air around us is a mixture of many gases and dust particles. It is the clear gas in which living things live and breathe. It has an indefinite shape and volume. It has no color or smell. It has mass and weight, because it is matter. The weight of air creates atmospheric pressure. There is no air in outer space.
Air is a mixture of about 78% nitrogen, 21% oxygen, 0.9% argon, 0.04% carbon dioxide, and very small amounts of other gases. There is an average of about 1% water vapour.
Animals live by aerobic respiration and need to breathe the oxygen in the air. In breathing, the lungs put oxygen into the blood, and send back carbon dioxide to the air. Plants need the carbon dioxide in the air to live. They give off the oxygen that we breathe. Without it we die of asphyxia.
Wind is moving air. This causes weather.
Air can be polluted by some gases (such as carbon monoxide), smoke, and ash. This air pollution causes various problems including acid rain and global warming.
Aircraft use propellers to move air over a wing, which allows them to fly. Pneumatics use air pressure to move things.
Related pages[change | change source]
References[change | change source]
- ↑"composition of air".
- ↑Zimmer, Carl (3 October 2013). Earth’s Oxygen: a mystery easy to take for granted. New York Times. 
Air Pollution Essay
1322 Words6 Pages
All living things use air and it must be clean to maintain life on earth. When air pollution becomes the subject, what do you think about? Smog, acid rain, and other forms of outdoor pollution are the common things people think about. Air pollution can also exist indoors as in closed ventilated areas that we surround. This makes the air that we breathe indoors inescapable and the pollution exist both indoor and outdoor. For example, hair spray usage indoor is polluting the air inside because of the emissions of toxic chemicals used to create the product are present within a spray of it. On a typical outdoor summer day in Fresno, the smog from vehicles exposed into the air which makes the air brown and can be seen miles away from highways.…show more content…
The sources used which gives off gases or particles are cooking oils, hair sprays, aerosols, household cleaning products such as bleach and Pinesol have the greater effect or even insecticide sources that kills rats, roaches, spiders and ants. According to World Health Organizations, “Cooking and heating with solid fuels on open fires or traditional stoves results in high levels of indoor air pollution. Indoor smoke contains a range of health-damaging pollutants, such as small particles and carbon monoxide.” The inadequate ventilation from using these products can increase the indoor air without outdoor air to dilute the emissions. The relative importance of a source used depends on how much emissions gives out on an object and evaporates in the air surrounding the user. Another factor from using building materials can give off high pollutant in some cases an improperly adjusted gas stove can emit high amounts of carbon dioxide than the properly adjusted one. Air pollution happens when sources are emitted into the air and it is caused by human activities from operating that source. Creating the pollution indoors is more harmful because it affects the air quality inside and it stay indoors if not ventilated properly. The activities from using the sources are causing these pollutions and we do not know that we are causing these pollutions to occur indoor. In a household with children and the