## Wikipedia - نوى التكاثف (ar) condensation nuclei (CN)

in atmospheric chemistry
https://doi.org/10.1351/goldbook.C01236
Particles, either liquid or solid, or ions upon which condensation of water vapour (or other substances) begins in the atmosphere. Condensation nuclei are usually very small hygroscopic aerosols ($$0.001\ \unicode[Times]{x3BC}\text{m}$$ to $$0.1\ \unicode[Times]{x3BC}\text{m}$$ in diameter), but these are not as abundant as the smaller particles. The number of CN which are active (initiate condensation) in a given air mass may be a function of the @[email protected] Usually CN are counted as the active nuclei at about 300% @[email protected], while cloud condensation nuclei (CCN) are counted as the number of active nuclei at @[email protected] less than or equal to 102%.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2182 [Terms] [Paper]