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Knowing the beginning of the periodic table

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Knowing the beginning of the periodic table

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The periodic table began with early attempts to classify elements, like Döbereiner's triads and Newlands' Law of Octaves. In 1869, Mendeleev organized elements by increasing atomic weight and similar properties, leaving gaps for undiscovered elements. In 1913, Moseley improved it by arranging elements by atomic number, creating the modern periodic table.

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Henry Moseley (1887–1915) was an English physicist who discovered that an element’s atomic number (number of protons) determines its identity, not its atomic mass. Using X-ray spectroscopy, he formulated Moseley's Law, linking X-ray frequencies to atomic numbers. This clarified the periodic table's structure, predicted missing elements, and modernized atomic theory. He tragically died young in World War I, but his work remains fundamental to science.

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Dmitri Mendeleev was a Russian chemist and inventor best known for creating the periodic table of elements. He organized the elements based on their atomic weights and properties, leaving gaps for elements that had not yet been discovered but predicting their characteristics accurately. His work laid the foundation for modern chemistry.

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Protons: Positively charged particles found in the nucleus (the center) of the atom.

Neutrons: Neutral particles (no charge) also located in the nucleus.

Electrons: Negatively charged particles that orbit the nucleus in various energy levels or shells.