The correct option is (c).
Explanation
Air is defined as a mixture of various gases that constitutes the Earth's atmosphere. In chemistry, mixtures are classified based on the uniformity of their composition, and solutions are defined as homogeneous mixtures of two or more substances.
Statement-wise Analysis
- Statement 1 is Correct: Air is a homogeneous mixture of gases. This means that the gases constituting air are mixed uniformly at the molecular level, and the composition is consistent throughout a given sample under standard conditions.
- Statement 2 is Incorrect: The two main constituents of air by volume are Nitrogen (approximately 78%) and Oxygen (approximately 21%). Argon (approx. 0.9%) and Carbon Dioxide (approx. 0.04%) are present in much smaller quantities and are considered minor constituents.
- Statement 3 is Correct: A solution is defined as a homogeneous mixture of a solute in a solvent. In the case of air, various gases are dissolved in other gases (primarily nitrogen acting as the solvent due to its largest proportion). Therefore, air is scientifically classified as a gaseous solution or a solution of gas in gas.
Key Takeaway
Air is a homogeneous mixture (solution) of gases, primarily composed of Nitrogen and Oxygen, which together make up about 99% of the atmosphere by volume.