"isotope" - key terms from Wikipedia

electromagnetic isotope	separation
fifth isotope
fissile isotope
heavy isotope
isotope
isotope	cartridges
isotope	effect
isotope	ratio mass
isotope	separation
laser isotope	separation
medical isotope	production
most stable isotope
new isotope
one stable isotope
operation isotope
oxygen isotope
oxygen isotope	ratio
parent isotope
stable isotope