1. The Element: Oxygen
By Mary Ann Estafanous

2. Properties of Oxygen
Name of Element : Oxygen 
Symbol of Element : O 
Atomic Number of Oxygen :  8
Atomic Mass: amu 
Melting Point: °C ( K)
Boiling Point: °C (90.15 K)
Number of Protons/Electrons in Oxygen : 8
Number of Neutrons in Oxygen : 8
Crystal Structure: Cubic 293 K: g/cm3
Oxygen is a very reactive element that easily forms compounds such as oxides. Oxygen is the second most electronegative element on the periodic table, next to fluorine. In most covalent bonds with oxygen the bonding electrons are shared unequally, resulting in a partial negative charge on the oxygen atom and a partial positive charge on the bonded atom.

3. Why is oxygen so important?
Oxygen is essential to human life. It makes up around 21% of the air we breathe and is part of the water we drink (H2O). Under standard temperature and pressure conditions, two oxygen atoms join to form dioxygen (O2), a colorless, tasteless and odorless gas.
Diatomic oxygen is essential for animal life because of its role in aerobic respiration -- in animal cells oxygen reacts with glucose C6H12O6 (from food) to release large amounts of energy plus water and carbon dioxide.

4. Oxygen in Carbohydrates
Oxygen reacts with and is a major component of glucose. Glucose is the most common carbohydrate.
Carbohydrate: any of a large group of organic compounds, including sugars, such as sucrose, and polysaccharides, such as cellulose, glycogen, and starch, that contain carbon, hydrogen, and oxygen, with the general formula Cm(H2O)n: an important source of food and energy for animals

5. Oxygen in the Body
Oxygen is transferred in the blood of humans by a protein called hemoglobin by attaching to an Iron ion.

6. Oxygen and the Earth
Between 1770 and 1780, Swedish pharmacist Carl Wilhelm Scheele, British clergyman Joseph Priestley and French chemist Antoine Laurent Lavoisier researched, documented and helped discover oxygen. The name oxygen was first used by Lavoisier in 1777.
Oxygen is most common element in the Earth’s crust (around 47%) and the third most common element in the Universe (but far less than hydrogen and helium, the two most common).
It is found in most rocks and minerals, and in numerous organic compounds. Oxygen is capable of combining with most elements. The liquid and solid forms of oxygen are a pale blue color and are strongly paramagnetic.

7. Oxygen in the Atmosphere
Ozone (O3) is an allotrope (different form) of oxygen that combines three oxygen atoms together. While ground level ozone is an air pollutant, the ozone layer in the Earth’s upper atmosphere provides protection from the suns harmful rays by filtering UV light.
The large amount of oxygen on Earth is supported by the oxygen cycle which involves the movement of oxygen between the air, living things and the Earth’s crust. Photosynthesis (a process that converts carbon dioxide into organic compounds using sunlight) plays a major role in this cycle.

8. Resources