Physics

Problem

A laboratory prepares equal initial activities of two pure isotopes, P and Q. Isotope P has a half-life of

1.0\,\text{day}

, whereas isotope Q has a half-life of

4.0\,\text{days}

. After

2.0\,\text{days}

, what is the ratio of the activity of isotope P to that of isotope Q,

A_{P}/A_{Q}

? a)

0.50

0.35

0.71

0.25