Reaktivita

Reaktivita, or reaktiivisuus, is the property of a chemical species that describes its tendency to participate in chemical reactions. In international usage it is commonly called reactivity. It is a broad concept that combines thermodynamic favorability with kinetic accessibility: a substance may be thermodynamically capable of reacting but slow to react if the activation barrier is high.

Several factors influence reaktivitasiinya: electronic structure determines how easily bonds can be broken or formed (ionization energy, electronegativity, bond dissociation energy). Steric effects can hinder or expose reactive sites. Temperature, pressure, and solvent affect reaction rates, and catalysts can lower activation barriers. In metals, reactivity often appears as the tendency to oxidize or corrode; in organic chemistry it describes sites of nucleophilic or electrophilic attack.

Measurement of reaktivita utilizes rate data (rate constants, half-lives) and activation energy, with models such as the Arrhenius equation. Reactivity is distinct from stability or hazard: a substance may be highly reactive but harmless under certain conditions, or conversely reactive only under specific triggers.

Common examples: alkali metals react vigorously with water; halogens show high reactivity that changes down the group; noble gases are largely inert. In materials science and biology, reaktivita also covers photoreactivity, electrochemical reactivity, and interactions with biological systems.

In education and research, reaktiiviteetti is used to explain trends across elements and functional groups and to guide synthesis, catalysis, and safety decisions.