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.
Description: The map showing location map of Dublin in Ireland. Dublin is the largest and capital city of Ireland situated at the coast of Irish Sea. The name Dublin is derived from the Irish name Dubh Linn, which means Black Pool. Dublin is the center of political, financial, commercial, media, transportation, and cultural activities. It is also ranked as Alpha Global City.