Why Is The Periodic Table Arranged The Way It Is?

In the 1860s, Dmitri Mendeleev, a lecturer at Saint Petersburg University, faced the challenge of organizing elements and creating an authoritative chemistry textbook. Despite limited knowledge of elements and incorrect data, he succeeded in writing 'Principles of Chemistry' and developed the periodic table. Mendeleev arranged elements by atomic weight and valence, predicting properties of undiscovered elements. The periodic table provides insights into atomic numbers, symbols, and weights, and organizes elements into periods and groups based on electron shells. Mendeleev's work laid the foundation for modern chemistry, offering a roadmap for known and unknown elements.

What information can be inferred from an element's atomic number?

What are the seven rows in the periodic table known as?