everyday science MCQ #48832

Newlands proposed an early octave pattern and Mendeleev left gaps for undiscovered elements. What did Moseley’s work later make the reliable organizing number for the long-form table?

everyday science MCQ #48832

  1. Question 1

    Q1. Newlands proposed an early octave pattern and Mendeleev left gaps for undiscovered elements. What did Moseley’s work later make the reliable organizing number for the long-form table?

    • A) Atomic mass only
    • B) Neutron count only
    • C) Atomic number
    • D) Density in grams per cubic centimetre only

    Answer: Atomic number

    Explanation: Henry Moseley showed in 1913 that bombarding elements with X-rays revealed a unique atomic number (proton count) for each element; arranging elements by atomic number resolved anomalies in Mendeleev's mass-based table and became the reliable organising principle of the modern periodic table.