A radioisotope has a decay constant of

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

Problem

0.035\,\text{day}^{-1}

. If it initially contains

8.0\times10^{20}

undecayed nuclei, how many nuclei remain after

20\,\text{days}

? (a)

8.0\times10^{20}

(b)

1.6\times10^{20}

(c)

4.0\times10^{20}

(d)

2.5\times10^{20}