Tallinn Pae Gymnasium, Tallinn, Estonia
Dubnium: The name dubnium originates from Dubna, the town famous for its oak trees (“Dub” means an oak tree in the Russian language), in Russia where it was first synthesized in 1970. As this element was discovered independently in the U.S.A. and Russia around the same time, we showed the oak roots in the form of the flags of both countries. Dubnium is an artificially produced radioactive element with an atomic number 105 whose most long-lived isotopes have mass numbers of 258, 261, 262 and others. Due to this fact the oak tree branches were depicted as isotopes and falling leaves designate alpha and beta rays emitted by those isotopes.
Jelena Glazkova, Tallinn Pae Gymnasium, Tallinn, Estonia
Number of isotopes:
* Haynes, W. M. (2011). CRC Handbook of Chemistry and Physics, 91st edition: http://www.hbcponline.com/ Retrieved April 7, 2011
** Winter, M. (2010). Home of the Periodic Table. Retrieved April 8, 2011, from Web Elements: http://www.webelements.com/