Consider the following constituent gases of the atmosphere : 1. Argon 2. Neon 3. Helium 4. Carbon dioxide Which one of the following is the correct descending sequence of the above gases in terms of the volume percentage?

The Earth's atmosphere is composed of various gases with distinct volume percentages. Argon is the most abundant among the listed trace gases, accounting for approximately 0.93% to 0.934% of the atmosphere by volume [1]. Carbon dioxide follows as the next most significant constituent, with historical concentrations around 0.03% to 0.036% (approximately 353 ppmv in older records) [2]. Neon and helium are present in much smaller trace amounts. Neon constitutes about 0.0018% (18.18 ppmv) of the dry air volume [1]. Helium is even less abundant, making up approximately 0.0005% (5.24 ppmv) [1]. Therefore, the correct descending sequence by volume percentage is Argon (1), Carbon dioxide (4), Neon (2), and Helium (3), which corresponds to the sequence 1-4-2-3.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Permanent Gases of The Atmosphere > p. 271
2. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY > atmosphErE. > p. 6