What differs between a radioactive isotope and a stable isotope? a. stable isotopes are shorter b. radioactive isotopes last longer c. radioactive isotopes last for less time d. there is no diffrence

Answer is: C. radioactive isotopes last for less time.

For example, polonium is rare and highly radioactive metal with no stable isotopes.  Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting polonium-210 (with a half-life of 138 days) in uranium ores.

On other hand, the half-life for the radioactive decay of U-238 (stable isotope) is 4.5 billion years and is independent of initial concentration.

more info ? ? i don't understand what the question is

explanation:

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.