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oxygen science definition
Symbol O
A nonmetallic element that exists in its free form as a colorless, odorless gas and makes up about 21 percent of the Earth's atmosphere. It is the most abundant element in the Earth's crust and occurs in many compounds, including water, carbon dioxide, and iron ore. Oxygen combines with most elements, is required for combustion, and is essential for life in most organisms. Atomic number 8; atomic weight 15.9994; melting point -218.4°C; boiling point -183.0°C; gas density at 0°C 1.429 grams per liter; valence 2. See Periodic Table.
Word History In 1786, the French chemist Antoine Lavoisier coined a term for the element oxygen (oxygène in French). He used Greek words for the coinage: oxy- means “sharp,” and -gen means “producing.” Oxygen was called the “sharp-producing” element because it was thought to be essential for making acids. Lavoisier also coined the name of the element hydrogen, the “water-producing” element, in 1788. Soon after, in 1791, another French chemist, J. A. Chaptal, introduced the word nitrogen, the “niter-producing” element, referring to its discovery from an analysis of nitric acid.
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