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  2. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    Oxygen is a chemical element; it has symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is the most abundant element in Earth's crust, and after hydrogen and helium, it ...

  3. Chemical bonding of water - Wikipedia

    en.wikipedia.org/wiki/Chemical_bonding_of_water

    Chemical bonding of water. Lewis Structure of H 2 O indicating bond angle and bond length. Water (H2O) is a simple triatomic bent molecule with C 2v molecular symmetry and bond angle of 104.5° between the central oxygen atom and the hydrogen atoms. Despite being one of the simplest triatomic molecules, its chemical bonding scheme is ...

  4. Water - Wikipedia

    en.wikipedia.org/wiki/Water

    Tetrahedral structure of water. In a water molecule, the hydrogen atoms form a 104.5° angle with the oxygen atom. The hydrogen atoms are close to two corners of a tetrahedron centered on the oxygen. At the other two corners are lone pairs of valence electrons that do not participate in the bonding. In a perfect tetrahedron, the atoms would ...

  5. Properties of water - Wikipedia

    en.wikipedia.org/wiki/Properties_of_water

    2 O; one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom. [25] Water is a tasteless, odorless liquid at ambient temperature and pressure. Liquid water has weak absorption bands at wavelengths of around 750 nm which cause it to appear to have a blue color. [3]

  6. Reactive oxygen species - Wikipedia

    en.wikipedia.org/wiki/Reactive_oxygen_species

    In chemistry and biology, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (O2), water, and hydrogen peroxide. Some prominent ROS are hydroperoxide (O 2 H), superoxide (O 2-), [ 1 ] hydroxyl radical (OH.), and singlet oxygen. [ 2 ] ROS are pervasive because they are readily produced from O 2, which is ...

  7. Oxygen evolution - Wikipedia

    en.wikipedia.org/wiki/Oxygen_evolution

    Photosynthetic oxygen evolution is the fundamental process by which oxygen is generated in the earth's biosphere. The reaction is part of the light-dependent reactions of photosynthesis in cyanobacteria and the chloroplasts of green algae and plants. It utilizes the energy of light to split a water molecule into its protons and electrons for ...

  8. Hydrogen bond - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_bond

    Water is unique because its oxygen atom has two lone pairs and two hydrogen atoms, meaning that the total number of bonds of a water molecule is up to four. [40] The number of hydrogen bonds formed by a molecule of liquid water fluctuates with time and temperature. [41]

  9. Covalent bond - Wikipedia

    en.wikipedia.org/wiki/Covalent_bond

    Covalent bond. A covalent bond forming H 2 (right) where two hydrogen atoms share the two electrons. A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms ...