Specialty Medical Coding Certification. 1  Hematology and Oncology â CHONCâ¢. 2  Internal Medicine â CIMCâ¢. 3  Interventional Radiology and Cardiovascular â CIRCCÂ®. 4  Obstetrics Gynecology â COBGCâ¢. 5  Ophthalmology â COPCâ¢. 6  Orthopaedic Surgery â COSCâ¢. 7  Otolaryngology â CENTCâ¢. 8  Pediatrics â CPEDCâ¢. FREE Practice Exam & Study Guide through Aug 31st.
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.
Oxygen, the second most abundant element on Earth, is found mainly in the crust. Although oxygen is most often thought of as an atmospheric gas, it is also one of the primary components of the silicate minerals that make up the vast majority of the Earth's crust.xygen, the second most abundant element on Earth, is found mainly in the crust. Although oxygen is most often thought of as an atmospheric gas, it is also one of the primary components of the silicate minerals that make up the vast majority of the Earth's crust.