The half life of a cobalt radio-isotope is 5.3 years. Wht strength will a milli-curie soure of the isotope have after a period of one year.

The half life of a radio isotope is 5 years . The fraction which will decay in 15 years , will be

The half life of a radio -isotope is four hour. If the initial mass of the isotope was 20g,the mass left after 24 hours undecayed is

The half life of a radio isotope is 3h. The mass of the isotope at time t=0 is 160 gm. What is the mass of the isotope left after 15 h ?

The half -life of cobalt-60 is 5.25 years. How long after a new sample is delivered, will the activity have decreased to about one third (1//3) of its original value-