A radioactive element present uranium ores, used in equilibrium using its decay services and products as a source of alpha rays. Its longest lived isotope is Ac 227 with a half-life of 21.6 years. Atomic number 89; melting point 1,050°C; boiling point (estimated) 3,200°C; specific-gravity (calculated) 10.07; valence 3. See Table at element.
a radioactive, metallic chemical factor (logo: Ac) with an atomic wide range of 89; present in uranium ores
A supposed steel, said by Phipson becoming found in commercial zinc; -- so named because particular of its substances tend to be darkened by experience of light.
A supposed chemical element found connected with zinc. Its chemical and physical properties have not been totally examined.
A radioactive material discovered by Debierne to occur inside residues staying from pitchblende after the removal for the uranium: a radio-element closely associated in its substance behavior to lanthanum, from which it's never as yet already been discovered possible to split up it completely.
a radioactive component of the actinide show; found in uranium ores