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.
The highest monthly average temperature in Dublin for July is 71 degrees. The lowest monthly average temperature in Dublin for January is 46 degrees. The most monthly precipitation in Dublin occurs in February with 2.8 inches. The air quality index in Dublin is 3% better than the national average. The pollution index in Dublin is 26% worse than the national average.