Alkuainetaulukko

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 way to understand and predict the behavior of elements.

The table is organized into rows called periods and columns called groups. Elements in the same period have the same highest electron shell being filled. Elements in the same group share similar chemical properties due to having the same number of valence electrons, which are the electrons in the outermost shell and are involved in chemical bonding.

The periodic table displays elements from left to right and top to bottom in increasing order of atomic number, which is the number of protons in the nucleus of an atom. The arrangement highlights trends in atomic radius, ionization energy, and electronegativity across periods and down groups.

Developed over time by many scientists, notably Dmitri Mendeleev in the 19th century, the modern periodic table is based on the quantum mechanical model of the atom. It serves as a comprehensive reference for chemists, providing insights into the relationships between elements and their potential reactions. The table is continuously updated as new elements are discovered or synthesized.