1911 ⟶ van den Broek Proposes Organization by Atomic Number
Antonius van den Broek proposes the idea that the elements o...
Year
1864
1869
1911
1913
🎵 Newlands Proposes Law of Octaves
John Newlands proposes the law of octaves, a precursor to the periodic law.⟶
Law of OctavesPeriodic LawChemistryJohn NewlandsElement Classification19th Century SciencePeriodic Table
United Kingdom🗓️ Mendeleev Publishes Periodic Table
Dmitri Mendeleev publishes the first modern periodic table, with the 66 known elements organized by atomic weights. The strength of his table was its ability to accurately predict the properties of as-yet unknown elements.⟶
ChemistryPeriodic TableMendeleevElements19th CenturyAtomic TheoryChemical PropertiesClassification
Russia⚛️ van den Broek Proposes Organization by Atomic Number
Antonius van den Broek proposes the idea that the elements on the periodic table are more properly organized by positive nuclear charge rather than atomic weight.⟶
ChemistryPeriodic TableAtomic Numbervan den BroekElements
Netherlands🔢 Atomic Number Concept Introduced
Henry Moseley, working from Van den Broek's earlier idea, introduces concept of atomic number to fix inadequacies of Mendeleev's periodic table, which had been based on atomic weight.⟶
Atomic NumberPeriodic TableHenry MoseleyAtomic PhysicsChemistryPeriodic LawEarly 20th Century Chemistry
United Kingdom🔢 Atomic Number Defined
Henry Moseley: defined atomic number⟶
Atomic NumberMoseleyPeriodic TableAtomic PhysicsChemistryEarly 20th Century Chemistry
United Kingdom