Two radioactive elements and (decay constant and respectively)

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

Problem

Two radioactive elements

A

and

B

(decay constant

= 10\lambda

and

\lambda

respectively), initially have the same number of nuclei. The ratio of nuclei of

A

and

B

left will be

1/e

after time: (1)

(10\lambda)^{-1}

(2)

(11\lambda)^{-1}

(3)

11 \times (10\lambda)^{-1}

(4)

(9\lambda)^{-1}