PhysicsEasy183×since 2002Q6123The activity of a radioactive material is 6.4×10−46.4 \times 10^{-4}6.4×10−4 curie. Its half life is 5 days. The activity will become 5×10−65 \times 10^{-6}5×10−6 curie after :A7 daysB15 daysC25 daysD35 daysCheck answerSkip