having a radiate form.
The animals are actiniform, furnished with numerous cleft tentacula, in the centre of which is the polygonal mouth.
The Ocean World: Louis Figuier
another word for actinoid
a contractile protein of muscle.
the property of radiation by which chemical effects are produced. Historical Examples In summer, when the maturing process advances, light and heat increase, and actinism relatively declines. The Reason Why Anonymous In the autumn, when the ripening period arrives, light and actinism give way to a greater ratio of heat. The Reason Why Anonymous The […]
a radioactive silver-white metallic element that glows blue in the dark, resembling the rare earths in chemical behavior and valence. Symbol: Ac; atomic number: 89; atomic weight: 227. Historical Examples Other radio-active substances have each several derivatives: actinium has nine, uranium has four. Inventors at Work George Iles actinium, an element or elementary substance obtained […]
- Actinium emanation
. a chemically inert, gaseous, short-lived isotope of radon that is a member of the . Symbol: An; atomic number: 86; atomic weight: 219. Historical Examples These are generally known as radium emanation, thorium emanation, and actinium emanation. A Brief Account of Radio-activity Francis Preston Venable noun a radioisotope of radon that is a decay […]
- 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