A common graph of versus time (in hours) is drawn for two different isotopes and

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

Problem

A common graph of

\ln N

versus time

t

(in hours) is drawn for two different isotopes

P

and

Q

. The two straight lines obtained have slopes

-0.35\,\text{h}^{-1}

and

-0.12\,\text{h}^{-1}

respectively. Which pair of half-life values is consistent with these observations? (a)

P

1.0\,\text{h}

;

Q

2.9\,\text{h}

(b)

P

5.8\,\text{h}

;

Q

2.0\,\text{h}

(c)

P

2.9\,\text{h}

;

Q

8.3\,\text{h}

(d)

P

2.0\,\text{h}

;

Q

5.8\,\text{h}