alkuainetaulukon

Alkuainetaulukko, often referred to as the periodic table, is a tabular arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties. It is a fundamental tool in chemistry, providing a systematic overview of all known elements and their relationships.

The horizontal rows of the periodic table are called periods, and the vertical columns are called groups. Elements within the same group typically share similar chemical characteristics due to having the same number of valence electrons. Periods, on the other hand, represent the filling of electron shells.

The periodic table organizes elements into blocks based on their electron configurations: s-block, p-block, d-block, and f-block. The s-block includes alkali metals and alkaline earth metals, the p-block contains nonmetals, metalloids, and some post-transition metals, the d-block comprises transition metals, and the f-block houses the lanthanides and actinides.

Key information typically found for each element includes its atomic number, symbol, name, atomic mass, and sometimes its electron configuration. The periodic table is invaluable for predicting chemical behavior, understanding bonding patterns, and identifying trends in properties such as electronegativity, atomic radius, and ionization energy. Its development is credited to Dmitri Mendeleev, who in 1869 arranged the elements known at the time based on atomic mass and recurring properties, leaving gaps for undiscovered elements. The modern periodic table is ordered by atomic number, as established by Henry Moseley.