Which of the following shows oxidation?

Appeared in: RRB Nsg. Superintendent-2026 (Shift -2nd)

Explanation

Oxidation is a chemical process that can be defined in several ways, including the addition of oxygen to a substance.
Chemically, oxidation is defined as the removal or loss of electrons from a molecule, atom, or ion.
This process is always accompanied by reduction, where another substance gains the electrons.
In many biological systems, oxidation occurs through the removal of hydrogen atoms (dehydrogenation), which also constitutes a loss of electrons.

Option A: The addition of hydrogen to a substance is the definition of reduction, the opposite process of oxidation.
Option B: The loss or removal of oxygen from a substance is a key characteristic of reduction, not oxidation.
Option D: The gain of electrons is the electronic definition of reduction. Oxidation is characterized by the loss of electrons.

Visual 1: Diagram: A simple illustration showing an atom losing an electron (oxidation) and another atom gaining an electron (reduction), explaining the mnemonic 'OIL RIG' (Oxidation Is Loss, Reduction Is Gain).
Visual 2: Table: A comparative table summarizing the key differences between oxidation and reduction concerning oxygen, hydrogen, electrons, and oxidation state.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition of Oxidation and Reduction (Redox Reactions) as background academic context rather than a clinical decision trigger.
Understanding redox reactions is fundamental in biochemistry. Cellular respiration, the process of generating ATP (energy), is a series of oxidation-reduction reactions.
Many metabolic pathways, such as the breakdown of glucose (glycolysis) and fatty acids (beta-oxidation), involve the oxidation of molecules to release energy.
Antioxidants, like Vitamin C and E, protect the body from damage by neutralizing harmful reactive oxygen species (free radicals) through redox reactions.

How to Approach the Question

First, identify the key term in the question, which is 'oxidation'.
Recall the different definitions of oxidation: addition of oxygen, removal of hydrogen, or loss of electrons.
Systematically evaluate each option against these definitions.
Option A, 'Addition of Hydrogen,' is a definition of reduction.
Option B, 'Loss of oxygen,' is also a definition of reduction.
Option C, 'Addition of oxygen,' directly matches a classical definition of oxidation.

Concept Tested & Keywords

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Practise the full RRB Nsg. Superintendent-2026 (Shift -2nd)

Attempt every question from this paper in a timed mock, then review the full solution for each one.