PhysicsMedium183×since 2002Q6115The activity of a radioactive material is 2.56 ×\times× 10^−-−3 Ci. If the half life of the material is 5 days, after how many days the activity will become 2 ×\times× 10^−-−5 Ci ?A30 daysB35 daysC40 daysD25 daysCheck answerSkip