Oxygen is in Group 16 of the periodic table. 1/5 of the atmosphere is oxygen and in mars atmosphere contains 0.15% oxygen. Oxygen is even the third most abundant element found in the sun, it also participates in the carbon-nitrogen cycle.

The word oxygen was originally from the Greek word "oxy genes". Lenanardo da Vinci explained that air should consist of at least two different gases. People say that Joesph Priestly was credited with the discovery of oxygen.

Water, we drink it everyday. Oxygen is presented in water or H2O for short (Hydrogen and Oxygen). Usually it is present in many organic compounds. The ozone layer even contains oxygen and can be very toxic.

21% of our atmosphere is made up of oxygen. In H2O oxygen makes up most of its weight. The atmosphere of Mars contains 0.15%

Some include,

• Gas is colourless, odourless, and tasteless
• Solid oxygen is blue

https://www.webelements.com/oxygen/

http://www.google.com/search?q=oxygen&safe=active&biw=1268&bih=441&source=lnms&tbm=isch&sa=x&ei=yh6uvo3vlaw_sqtnhikiag&ved=0cayq_auoaq&surl=1