The symbol for the chemical element oxygen is "O." In the periodic table, oxygen is positioned in group 16 and is atomic number 8. As a vital element for life, oxygen plays a crucial role in cellular respiration, where it helps organisms convert food into energy. It is also a key component of water (H2O) and is found in many organic and inorganic compounds. Oxygen is a colorless, odorless gas at room temperature and exists in diatomic form (O2) in the atmosphere. Its high electronegativity makes it an important atom in forming various chemical bonds.