issb general knowledge MCQ #627

Hardest natural substance on Earth?

issb general knowledge MCQ #627

  1. Question 1

    Q1. Hardest natural substance on Earth?

    • A) Gold
    • B) Iron
    • C) Diamond
    • D) Platinum

    Answer: Diamond

    Explanation: Diamond is the hardest known natural material. This fact often appears in ISSB academic and general knowledge sections.