The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 150 grams of a radioactive isotope, how much will be left after 3 half lives?
round your answer to the nearest gram.

Question

The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 150 grams of a radioactive isotope, how much will be left after 3 half lives?
round your answer to the nearest gram.

anonymous · Answer

Start with 150, divide that by two
divide that number by two
divide that number by two

ribhu · Answer

after ist half life remaining would be 75gm

ribhu · Answer

second half life remaining would be 75-37.5 = 37.5 gm.

ribhu · Answer

after third half life 37.5-37.5/2 =37.5/2 = 18.75 gms

ribhu · Answer

18.75 gm of isotope would be remaining

anonymous · Answer

Thank you so much :) may I ask you where you got the 2 from? when you divide 150/2 just so I know what to do for next time.

ribhu · Answer

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