2,014
edits
Changes
Jump to navigation
Jump to search
Line 1:
Line 1: − + − + − + +
substantial rewrite to get closer to, um, reality.
Oxygen is a chemical [[element]] vital for life. Under normal conditions it is a colorless odorless [[gas]] consisting of two oxygen [[atom|atoms]] which has the chemical formula O<sub>2</sub>. This means it is diatomic.
'''Oxygen''' is a chemical [[element]]. Its atomic number, and hence the number of [[proton]]s and [[electron]]s it contains, is 8, and its atomic mass is slightly under 16, since it also has 8 [[neutron]]s (a slight amount of mass is "lost" in the energy contianed in the subatomic bonds).
Approximately 20% of the [[atmosphere]] is made up of oxygen.
Under [[normal condition]]s it is a colorless, odorless [[gas]] consisting of two oxygen [[atom|atoms]] which has the chemical formula O<sub>2</sub>. This means it is diatomic. Approximately 20% of the [[atmosphere]] is made up of oxygen. Oxygen also forms a triatomic molecule called [[ozone]] (O<sub>3</sub>), which although unstable under normal conditions, is a very important ingredient in the upper atmosphere.
Oxygen in a concentrated form is explosive. It is the component of all [[combustion]] reactions and produces [[carbon dioxide]].
Oxygen is highly reactive, and in many other elements and compounds undergo [[exothermic reaction]]s with it (they [[combustion|burn]] or rust). If it were not for its continual replenishment as a waste product of plant [[photosynthesis]], the atmospheric oxygen would disappear, forming compounds with other chemicals at the earth's surface.
Many animals depend upon oxygen as a highly efficient ingredient for breaking down food for energy, due to its reactivity. Those that do not are called "anaerobic", meaning "without air", and include many important bacteria.
[[Category:Chemistry]]
[[Category:Chemistry]]