uranium

uranium

 [u-ra´ne-um]

a chemical element, atomic number 92, atomic weight 238.03, symbol U. (See Appendix 6.)

u·ra·ni·um (U),

(yū-rā'nē-ŭm),

A radioactive metallic element, atomic no. 92, atomic wt. 238.0289, occurring mainly in pitchblende and notable for its two isotopes: ²³⁸U and ²³⁵U (99.2745% and 0.720%, respectively, the rest being made up by ²³⁴U), ²³⁵U being the first substance ever shown capable of supporting a self-sustaining chain reaction.

[G. myth. character, Uranus]

u·ra·ni·um

(U) (yŭr-ā'nē-ŭm)

A radioactive metallic element, atomic no. 92, atomic wt. 238.0289, occurring mainly in pitchblende and notable for its two isotopes: ²³⁸U and ²³⁵U (99.2745% and 0.720%, respectively, the rest being made up by ²³⁴U), ²³⁵U being the first substance ever shown capable of supporting a self-sustaining chain reaction.

[G. myth. character, Uranus]