Development of the Periodic Table

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Across
  1. 4. Who proposed the Law of Octaves?
  2. 5. How is the Modern Periodic Table arranged?
  3. 6. What does the number of protons represent?
Down
  1. 1. Who formed the triads of Elements?
  2. 2. Who organized the periodic table based on atomic numbers?
  3. 3. Who developed a periodic table similar to Mendeleev's?