everyday science MCQ #1895

Which of the following substances is the lightest?

everyday science MCQ #1895

  1. Question 1

    Q1. Which of the following substances is the lightest?

    • A) Hydrogen
    • B) Nitrogen
    • C) Uranium
    • D) Oxygen

    Answer: Hydrogen

    Explanation: Hydrogen is the lightest substance (element) with an atomic mass of approximately 1 u and density of 0.0000899 g/cm³ at STP, making it the least dense element in the universe.