The maximum amount of gas which is present in the atmospheric air is -

Appeared in: UPPSC 2023

Explanation

Nitrogen is the most abundant gas in Earth's atmosphere, making up approximately 78.1% of the air by volume.
It is a diatomic, relatively non-reactive gas at standard conditions, which serves to dilute oxygen and prevent rapid, uncontrolled combustion.
As a fundamental component of amino acids, proteins, and nucleic acids (DNA/RNA), nitrogen is essential for all forms of life through the nitrogen cycle.

Option B: Carbon dioxide is a trace gas, present at a concentration of only about 0.03% to 0.04%, which is far less than nitrogen.
Option C: Ozone is present in very minute trace amounts, mainly in the stratosphere, and is not a major component of the air we breathe at sea level.
Option D: Oxygen is the second most abundant gas, not the most abundant. It comprises about 20.93% of the atmosphere.

Clinical Relevance

Nursing practice connection: Knowing Composition of Atmospheric Air helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the composition of air is fundamental in respiratory therapy. The 21% oxygen concentration in 'room air' is the baseline for administering supplemental oxygen.
Changes in atmospheric gas concentrations, such as in enclosed spaces or at high altitudes, have direct physiological effects that nurses must recognize, like hypoxia (low oxygen) or hypercapnia (high carbon dioxide).
Knowledge of atmospheric gases is crucial for interpreting blood gas analysis, as the partial pressure of these gases in the air directly influences their exchange in the lungs.

How to Approach the Question

Identify the core question: The question asks to identify the gas that is most abundant ('maximum amount') in the atmosphere.
This is a factual recall question based on general science knowledge.
Recall the approximate percentages of major atmospheric gases: Nitrogen is about 78%, Oxygen is about 21%, and all other gases are present in much smaller amounts.
Compare the options to these known facts. Nitrogen has the highest percentage.
Eliminate the other options based on their significantly lower concentrations: Oxygen (21%), Carbon Dioxide (~0.04%), and Ozone (trace amounts).
Select Nitrogen as the correct answer because it has the highest concentration.

Concept Tested & Keywords

QMOZBuvHOwoMyCQbbZs8Yp

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart B (pp 233-449 of 464) p. 48-50

E6 Biochemistry U Satyanarayana— Part 2 (pp 421-820 of 840) p. 292-294

Practise the full UPPSC 2023

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