oxygen

Name oxygen
Symbol O
Atomic Weight 15.9994
Atomic Number 8
CAS ID 7782-44-7
Group Number 16
Group Name Chalcogen
Period Number 2
Origin of Name Greek, oxy genes = "acid forming."
Year Discovered 1774
Discovery Credits J. Preistley at Leeds, UK, and independently by C. W. Scheele at Uppsala, Sweden.
Class Non-Metallic
Color Colorless as a gas, liquid is pale blue.
Standard State Gas at 77 F & 298 K
Description Colorless, odorless gas present in the atmosphere. Very reactive and forms oxides of all elements except He, Ne, Ar, and Kr. Moderately soluble in water (30.8 cc per liter) at 293 K. Used in steel making, metal cutting, chemical industry.

Diagnostic tests: 
The direct detection of oxygen in minerals is not practical using simple tests. Indirect methods are generally used.
The presence of oxygen in minerals in the form of H2O or OH is detected by using the closed-tube test and observing the formation of colorless drops of water (H2O) on the walls of the tube when the sample is heated.
More advanced techniques use Ramon Spectroscopy, Neutron Activation Analysis, and Isotopic Mass Spectrometer measurements to analyze for oxygen.

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