Reduction-oxidation reaction

• Oxidation is gain of oxygen.
• Reduction is loss of oxygen.

https://www.wikiwand.com/en/Redox

http://www.chemguide.co.uk/inorganic/redox/definitions.html

Oxidation state. http://chem.libretexts.org/Core/Analytical_Chemistry/Electrochemistry/Redox_Chemistry/Oxidation-Reduction_Reactions

An example are Halogen displacement reactions.

Redox reactions are analyzed well using ionic equations

Oxygen and oxides

Rusting

Old definitions still used in Organic chemistry

• Oxidation is loss of hydrogen.
• Reduction is gain of hydrogen.