Home › CISF Constable › Science › Pure Substances and Mixtures › Which of the following is a pure substance?
Which of the following is a pure substance?
AAir
BMethane
CSugar solution
DMilk
Answer & Solution
Correct answer: B. Methane
1. A pure substance has a fixed composition made of one kind of particle.
2. Air, sugar solution and milk are all mixtures of more than one substance.
3. Methane (CH₄) is a single compound, so it is a pure substance.
_Source: RRB Group D CEN-02/2018 PYQ, Q.21._