In reply to Jones Beene's message of Sat, 27 Jan 2007 16:46:03 -0800: Hi, [snip] >3) Barium has such an isomer called Ba-135m. 135Ba is itself about 6.6% >of all barium and the isomer is a fraction of that which depends on how >long, and how "hot" was the ore from which the barium was extracted. >Barium ore invariably contains some radium. The gamma of barium is not >all that strong, as with hafnium, or else the military would already be >using it instead - as there is orders of magnitude more barium than >halfnium. Also, halfnium with a high level of activity can be extracted >from control rods which were used on nuclear submarines - thus it is >almost a waste product.
...however Ba135m only has a half-life of 1.2 days, whereas Hf-178m isomere has a half-life of 31 years. Consequently there is unlikely to be any significant amount of the Ba isomere present. Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means.
