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Periodic classification of elements HTML5


In 1869 the Russian chemist D. I. Mendeleev discovered that pure chemical elements (containing a single kind of atom) could be classified in a table, in families, according to the number of protons in their nuclei. This number, called the atomic number, increases from top to bottom and from left to right on this table. The elements arranged in the same column have similar chemical properties.

Click an element to see its properties.

Learning goals

  • To explore the Periodic Table and the properties of the elements.

Learn more

Each element in the table is represented by a symbol and by two numbers, the first  being the atomic number (number of protons) and the second the atomic weight (number of protons + neutrons). The…

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