Question

A radioactive substance is decaying with $t_{1/2}=30$ days. On being separated into two fractions, one of the fractions, immediately after separation, decays with $t_{1/2}=2$ days. The other fraction, immediately after separation would show:

• A. constant activity
• B. increasing activity
• C. decay with $t_{1/2}=30$ days
• D. decay with $t_{1/2}=28$ days

Answer 1

The correct option is B increasing activity

From basic radioactivity, we know that separation of nuclei, giving one finite $t_{1/2}$ would lead to another unstable (in this case) nuclei.
So option B correct.