oxygen was discoveredby?
829151
Oxygen was discovered for the first time by a Swedish Chemist, Carl Wilhelm Scheele, in 1772. Joseph Priestly, an English chemist, independently, discovered oxygen in 1774 and published his findings the same year, three years before Scheele published. Antonie Lavoisier, a French chemist, also discovered oxygen in 1775, was the first to recognize it as an element, and coined its name "oxygen"
411114
He was a chemist who discovered guncotton and ozone.  I'm sure Wiki would have an entry on him, and maybe some actual refrences
119171
The first organisms to live on the earth belonged to the kingdom archaebacteria.
294431
Nucleic acids were discovered in 1869 by Johann Friedrich Miescher (1844-1895), who called the material 'nuclein' since it was found in the nucleus. It was later discovered that prokaryotic cells, which do not have a nucleus, also contain nucleic acids
588452
Moissan was the first to *isolate* fluorine, no small feat - but the first person to identify it as a chemically-unique element (though in combination) was Scheele in 1771.
440690
There is some dispute over who discovered oxygen.  Joseph Priestley and Antoine Lavoisier both worked on the discovery of oxygen.  Lavoisier published his work first, but I believe that Priestly did his work first.\n\nAntoine Lavoisier named hydrogen, but it was generated and described in earlier experiments by Theophrastus Bombastus von Hohenheim, Robert Boyle, and Henry Cavendish.
898426
http://en.wikipedia.org/wiki/Chemical_oxygen_generator
951358
Well whether or not it was discovered doesn't really matter. The fact that there is a symbiotic, mutualistic relationship between plants (producers) and all other organismsis quite important.  The plants depend on humans and animals for CO2 (carbon dioxide) which we exhale as a by-product of cellular respiration. \n\nThe plants in turn use that to build simple starches as their food source through the process of photosynthesis.  Then the by-product of the plants cellular respiration is Oxygen which the humans and animals all need to survive.\n\nIf we as humans didn't understand this important relationship that exists we in our ignorance may destroy the plant life that exists on earth (think Amazon Jungle and deforestation).  Without the plants we have no oxygen, without oxygen we DIE!\n\nThat's pretty significant don't you think?
72874
Nitrogen was discovered by Daniel Rutherford who was a student who needed a dissertation in order to finish his medical degree. However, all references I can find say he did this in 1772. \n\nBromine was prepared by Carl Löwig in about 1825 before starting his freshman year at Heidelberg. With winter exams and holidays, he was delayed in studying it further as his professor had requested, and another chemist Antoine-Jérôme Balard, published a paper describing the new element.  Balard was given the credit for discovering the new element.
943424
Oxygen itself is a gas of course.\nIn most kind of crystals you find oxygen atoms (or ions).\n\nTh
557949
oxygen...almost everywhere, anyway.
1103330
My thought is air as well. Air is composed of around 2/3s part of Nitrogen. Oxygen is a much smaller amount
662214
the chemical changes between oxygen and hydrogen that create of one molecule of water.
795053
While, indeed, Michał Sędziwój first wrote about oxygen. \n\n A Swedish person named Carl Wilhelm Scheele was a little more scientific in his description and used scientific methods. But, he did not published his findings until after the discovery of Oxygen by Joseph Priestley. Priestley published his discovery, consequently Priestley is usually given the credit.\n\nGet an "A".
875787
Well, this happened once before.  Originally the earth had a very low concentration of atmospheric oxygen and oxygen was toxic to most organisms (they were all single celled back then).  But as organisms started to develop photosynthesis, oxygen was released into the atmosphere in huge amounts causing a massive extinction.  Now most organisms need or tolerate oxygen.  I'm not sure what would happen if the %O2 was increased now......I bet that plants wouldn't like it though.
1070133
oxygen, nitrogen, every fuckin mineral and more on the periodic table...take chemistry
129728
According to current theory, 4 billion years ago (4 bya) the atmosphere had no free oxygen.\n\nAbout 3 bya, cyanobacteria evolved, which produce oxygen as a waste product of their photosynthesis.  This oxygen was poison for many forms of life, resulting is mass extinctions.\n\n2.5 bya, there was enough free oxygen in the atmosphere for organisms with modern oxygen based metabolisms to evolve.\n\nSo, sometime between 3 bya and 2.5 bya, fire became possible.