Which of the given statements is incorrect? 

The composition of oxygen in the air is the maximum.

The correct answer is option 2. The composition of oxygen in the air is the maximum.

The incorrect statement is: The composition of oxygen in the air is the maximum.

Air is indeed a mixture of gases, with nitrogen being the most abundant component (about 78%) and oxygen making up approximately 21%, along with trace gases.

The envelope of air surrounding the Earth is referred to as the atmosphere.

Aquatic plants and animals use dissolved oxygen in the water for various physiological processes. Oxygen dissolves in water and is crucial for the survival of aquatic organisms.

However, the statement "The composition of oxygen in the air is the maximum" is incorrect. While oxygen is an important component of the air, it does not constitute the majority. Nitrogen is the most abundant gas in the Earth's atmosphere, making up about 78% of the air.