Which statement defines oxidation?

• A. Gain of electrons
• B. Loss of electrons
• C. Release of neutrons
• D. Absorption of heat

Answer: (B)

Oxidation is the loss of electrons in a chemical reaction, which increases the oxidation state of the element involved. In redox reactions, one substance loses electrons (is oxidized) and another gains those electrons (is reduced). A common example is iron reacting with oxygen in moist conditions, where iron loses electrons and forms iron oxides. In soils, redox processes influence nutrient availability and soil color, because changes in oxidation state of elements like iron and manganese alter how they move and appear. This concept is fundamentally different from gaining electrons (that’s reduction), releasing neutrons (a nuclear process), or absorbing heat (a heat-related change not describing oxidation).