An isotope has an initial activity of 120 Bq. 6 days later its activity is 15 Bq. The half-life is? By: Sunday|Published on: Jan 11|Categories: Physics JAMB| 0 comments A. 3 days B. 2 days C. 1 day D. 4 days Correct Answer: Option A = 3 days Users Also Read These:The count rate of an alpha-particle source is 400…How many days are allowed in life insurance as days…The half life of a radioactive substance is 14 days.…Which of the following decreases when a given mass…A radioactive substance has a half-life of 20 days…SEE ALSO A machine has a velocity ratio of 4; if it requires 800N to overcome a load of 1600N. What is the efficiency of the machine?