John wanted to know about the composition of air. He asked Sam to explain it to him whether air is composed of a single component or more than one component. To reply this query Sam made the following statements:
Statement I: Air is a mixture of gases, water vapour and dust particles.
Statement II: Air is composed of only one gas that is nitrogen.
Statement III: Air is composed of two gases, nitrogen and oxygen only.
Statement IV: Air is made up of more than one components.
Which of the above statement(s) are correct?
Only II and IV
Air is a mixture of gases, water vapour and dust particles. Nitrogen and oxygen are the major components of air. The other gases are carbon dioxide, water vapour, noble gases, etc. The composition of air is not fixed and varies slightly from place to place. Nitrogen occupies 78% of the air and Oxygen occupies 21% of the air, and hence nitrogen and oxygen are the major components of air.