All the novel gases present in our air are monoatomic............they are six in number 1.Helium---with atomic number 22.Neon----with atomic number 103.Argon---with atomic number 184.Krypton---with atomic number 365.Xenon--with atomic number 546.Randon---with atomic number 86.................if its help u then u know what u have to do........enjoy ur study......and best of luck for ur exam

Air Constituents

Air is a mixture of various gases, and it consists of several different constituents. The major constituents of air are nitrogen, oxygen, argon, and carbon dioxide, along with traces of other gases such as water vapor, helium, neon, and methane. However, not all of these constituents are monoatomic.

Monoatomic Gases

Monoatomic gases are those that exist as single atoms, meaning they are not bonded to any other atoms. These gases are classified as noble gases, as they have filled electron shells and are chemically inert. The noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).

Identifying the Monoatomic Constituent

To determine which constituent of air is monoatomic, we need to consider the options provided:

a) Argon: Argon is a noble gas and exists as single atoms (Ar) in its natural state. Therefore, it is a monoatomic gas.

b) Water vapor: Water vapor (H2O) is not a monoatomic gas. It consists of two hydrogen atoms and one oxygen atom bonded together.

c) Oxygen: Oxygen (O2) exists as a diatomic gas, meaning it consists of two oxygen atoms bonded together. It is not a monoatomic gas.

d) Nitrogen: Nitrogen (N2) is also a diatomic gas, composed of two nitrogen atoms bonded together. It is not monoatomic.

Conclusion

Among the given options, only argon (Ar) is a monoatomic gas, as it exists as single atoms. Therefore, the correct answer is option 'A' - Argon.