a chemically inert, gaseous, short-lived isotope of radon that is a member of the . Symbol: An; atomic number: 86; atomic weight: 219.
These are generally known as radium emanation, thorium emanation, and actinium emanation.
A Brief Account of Radio-activity Francis Preston Venable
a radioisotope of radon that is a decay product of radium. Symbol: An or 219Rn; atomic no: 86; half-life: 3.92s
another name for actinide
- Actinium series
the radioactive series that starts with uranium 235 and ends with a stable isotope of lead of mass number 207. noun a radioactive decay series that starts with uranium-235 and ends with lead-207
a combining form with the meaning “ray, beam,” used in the formation of compound words, with the particular senses “radiation” in the physical sciences (actinometer) and “having raylike structures,” “radiate in form” in biology (actinomyces; actinopod). combining form indicating a radial structure: actinomorphic indicating radioactivity or radiation: actinometer before vowels actin-, word-forming element meaning “pertaining […]
any of several spherical or rod-shaped, aerobic, parasitic bacteria of the genus Actinobacillus, certain species of which, as A. mallei, are pathogenic for animals.
an infectious disease of cattle, domestic animals, and occasionally humans, resembling actinomycosis and caused by the bacterium Actinobacillus lignieresii. noun (vet science) a disease of cattle and sheep, caused by infection with an Actinobacillus lignieresii and characterized by soft tissue lesions, esp of the tongue Also called wooden tongue, woody tongue, cruels