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 is the third most abundant element in the Universe today, and in the very, very far future, may even have the opportunity to rise further as hydrogen (and then possibly helium) falls from its perch.