What differs between a radioactive isotope and a stable isotope?

a. stable isotopes are shorter
b. radioactive isotopes last for less time
c. radioactive isotopes last longer.
d. there is no difference

 A radioactive isotope is emitting particles such as a fast moving electron or positron (radiation) and this is changing its structure. Eventually it may reach a stable configuration and will no longer decay. An stable isotope is simply a name for a form of an element which is chemically identical to other atoms of the element but with a different number of neutrons. I hope this helps!

I’d have to say no because without oxygen in the water the fish would all be dead. so if you want to fish for dead fish, pick the ponds with the lowest oxygen concentrations.