Elementlar

Elementlar (chemical elements) are the fundamental substances that compose all matter. Each element is defined by a unique number of protons, its atomic number, and cannot be broken into simpler substances by ordinary chemical means. As of recent years, 118 elements have been confirmed, and they are organized in the periodic table.

Elements are typically categorized as metals, nonmetals, or metalloids, and they appear in groups and periods on the periodic table. Natural elements occur in Earth's crust, oceans, and atmosphere, while synthetic elements are produced in laboratories and tend to be unstable. Isotopes are variants of an element with different neutron counts.

An atom consists of a nucleus of protons and neutrons, surrounded by electrons in orbitals. The arrangement of electrons (the electron configuration) largely determines an element’s chemical properties. The periodic table reveals repeating patterns, called periodic trends, such as increasing electronegativity across a period and larger atomic radii down a group.

Elements are formed in cosmic processes: the lightest elements emerged during the Big Bang, while heavier elements are synthesized in stars and during supernovae. On Earth, elements occur in minerals, water, and organic matter. They are essential for industry, biology, medicine, and technology, enabling everything from fuels to pharmaceuticals and electronics.

Historically, many elements were known to ancient civilizations. The modern arrangement into a periodic table was developed in the 19th century by Dmitri Mendeleev, who left gaps for yet undiscovered elements. Since then the table has evolved with new discoveries, including synthetic transuranic elements, refining our understanding of chemical behavior.