actinium

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actinium

 (Ac) [ak-tin´e-um]
a chemical element, atomic number 89, atomic weight 227. (See Appendix 6.)

ac·tin·i·um (Ac),

(ak-tin'ē-ŭm),
An element, atomic no. 89, atomic wt. 227.05; it possesses no stable isotopes and exists in nature only as a disintegration product of uranium and thorium.
[G. aktis, a ray]

actinium

/ac·tin·i·um/ (Ac) (ak-tin´e-um) a chemical element, at. no. 89.

actinium (Ac)

a rare, radioactive metallic element. Its atomic number is 89; its atomic mass is 227. It occurs in some ores of uranium.

ac·tin·i·um

(Ac) (ak-tin'ē-ŭm)
An element, atomic no. 89, atomic wt. 227.05; it possesses no stable isotopes and exists in nature only as a disintegration product of uranium and thorium.
[G. aktis, a ray]

actinium

a chemical element, atomic number 89, atomic weight 227, symbol Ac. See Table 6.