funnie thing is: in da dot pt, it actually mentions CHEMICAL properties.... so half life, intensity of radiation would be redundant... cuz they r nuclear properties... my tutor told me this btw, whereas, my chem teacher said dat board os prolly got confused wif chemical n nuclear for fun.... if a question is asked how ever, i would stick both chemical and nuclear properties in....
newaz, here's wut i got:
tc-99m
nuclear: relatively short half life (6 hrs) hence, it won't remain in the body for too long to cause any major damage to body tissues...
relative weak yet penetrable radiation emmited (gamma only) so that detectors out side body can detect the emission while it causes least damage to body tissues
chemical:
its oxidation number can be easily altered to attach to different biologically active substrates, hence easily making it specific to individual organs...
na-24
nuclear: relative short half life (15 hrs) so that it is long enuf for the workers to work out the leak, short enuf to not leave any permanent threate to the water way
intensity (as above... )
chemcial: ionically bonded to cl, hence dissolvable in water, making it suitable to detect pipe leaks...