The half-life of a radioactive sample is 30 days

PHYSICS · Single correct · A Level · Physics · Nuclear physics · Nuclear physics

Problem

The half-life of a radioactive sample is 30 days. After approximately how many days will its activity reduce to

20\%

of its initial value? (a)

60\ \text{days}

(b)

90\ \text{days}

(c)

70\ \text{days}

(d)

42\ \text{days}