issb general knowledge MCQ #635

Which element has atomic number 1?

issb general knowledge MCQ #635

  1. Question 1

    Q1. Which element has atomic number 1?

    • A) Helium
    • B) Hydrogen
    • C) Lithium
    • D) Carbon

    Answer: Hydrogen

    Explanation: Hydrogen has atomic number 1 on the periodic table. Work each step carefully; ISSB math rewards accuracy under time pressure.