Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table and is a highly reactive nonmetallic element and oxidizing agent that readily forms compounds (notably oxides) with most elements. Photosynthesis releases oxygen, and respiration consumes oxygen.xygen constitutes 49.2% of the Earth's crust by mass and is the major component of the world's oceans (88.8% by mass). Oxygen gas is the second most common component of the Earth's atmosphere, taking up 20.8% of its volume and 23.1% of its mass (some 10 15 tonnes).
The River Liffey (Irish: An Life) is a river in Ireland, which flows through the centre of Dublin.
Dublin (/ËdÊblÉ¨n/ , Irish: Baile Ãtha Ã¡tha [cliath:blÊ²a]) ËklÊ²iÉh is the capital and largest city Of. Ireland dublin is in the province Of leinster On'ireland s east, coast at the mouth of The River. liffeyublin is administered by a City Council. The city is listed by the Globalization and World Cities Research Network (GaWC) as a global city, with a ranking of Alpha-, placing it among the top thirty cities in the world.