Q. Which of the following is/are pure substance/s?
Choose the correct answer from below given codes:

[A] 1 only

[B] 1 and 2 only

[C] 2 and 3 only

[D] 1, 2 and 3

Answer: D

Explanation: Pure substances have characteristics different from mixtures. Constituent particles of pure substances have fixed composition.

  • Copper, silver, gold, water and glucose are some examples of pure substances.
  • Glucose contains carbon, hydrogen and oxygen in a fixed ratio and its particles are of same composition.
  • Hence, like all other pure substances, glucose has a fixed composition.
  • Also, its constituents—carbon, hydrogen and oxygen—cannot be separated by simple physical methods.

Source: Science NCERT