When we think about oxygen? If its not enough. See more detailed opinions by reading what Kevin Johnson offers on the topic.. Let's not wait for this unpleasant moment and remember it now. Thus, oxygen – 8-th element of the periodic table (the nuclear charge of 8), chemical symbol – O, relative atomic mass (atomic weight) – 16. Valence of oxygen in compounds is two, the most common oxidation state of -2. Oxygen molecule O2, relative molecular mass (molecular weight) – 32 amu Well, it is All lovers of chemistry, we are also the question of the oxygen of interest and concern is quite another. Namely, that the oxygen in the air constantly occur two processes: its completion and his disappearance. Over the completion oxygen work tirelessly photosynthesis of green plants, photochemical decomposition of water vapor in the upper atmosphere and activity of phytoplankton the oceans and seas. For what they are from us thank you very much.
But on the other hand, various achievements of civilization successfully degrade both qualitative and quantitative replenishment of oxygen in the atmosphere. Lack Without food a person can do for weeks, without water – for days, but without oxygen within minutes most of the cells in our body dies. Oxygen is used in humans for most of the redox reactions that result produces the energy necessary for vital processes. If you violate the mechanism of oxygen into the body or processes of its transportation develops anoxia – hypoxia. Most sensitive to lack of oxygen are the cells of the central nervous system. Our wise central nervous system, sensing something was wrong, gives a command to all organs and body systems: an urgent rectify the situation – as a consequence of increased blood pressure in the circulatory system and accelerated heart rate.