Oxygen Facts

Oxygen Facts
Oxygen (O) has an atomic number of eight. This odorless, colorless gas has eight protons in the nucleus, and is pale blue in its liquid and solid states.
Interesting Oxygen Facts:
One fifth of the Earth's atmosphere is made up of oxygen and is the third most abundant element in the universe by mass.
Oxygen is the most abundant element by mass in the Earth's biosphere.
The high concentration of oxygen in the atmosphere is a result of Earth's oxygen cycle, which is predominantly driven by photosynthesis of plants.
Leonardo da Vinci first proposed that air was made up of two gases, one for breathing and one for fueling fire.
Joseph Priestly is traditionally credited with discovering oxygen in 1774.
Carl Wilhelm Scheele possibly discovered oxygen the year before, but his work was not published until after Priestly's.
At normal pressure and temperature, molecules of oxygen bind to form dioxide, or O2, which is present in the atmosphere.
It is a member of the chalcogen group on the periodic table and very easily forms compounds with elements except helium or neon.
Due to its presence in water, oxygen makes up most of the mass of all living things.
It is used in cellular respiration for all life.
An allotrope of oxygen is ozone (O3), which forms the upper atmospheric ozone layer and absorbs UV radiation from the sun.
Oxygen can be produced for commercial use by the fractional distillation of liquefied air, as well as other methods.
Under normal conditions, fresh water contains about 6.04 mL of oxygen per liter, while sea water contains about 4.95 mL of oxygen per liter.
Naturally occurring oxygen is made of three stable isotopes: O-16, O-17, and O-18.
O-18 is the most abundant isotope of oxygen, with a 99.762% occurrence.
Oxygen has a paramagnetic property.
Oxygen plays an important role in the high concentration of life in the polar oceanic regions, as oxygen is water soluble at extremely low temperatures.
Green algae and cyanbacteria are believed to be responsible for the production of as much as 70% of the free oxygen found in nature.
Free oxygen gas was nearly non-existant on Earth before the appearance of photosynthetic organisms about 3.5 billion years ago.
Oxygen is commercially produced for a wide variety of industries and uses, including medical uses for bottled oxygen.

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