Subject: Physical Chemistry · Chapter: Chemical Kinetics · Topic: Chemical Kinetics – General · Exam: NET JUNE 2013 · Marks: 2 · Difficulty: Medium
A radioisotope ${ }^{41} \mathrm{Ar}$ initially decays at the rate of 34, 500 disintegrations/minute, but decay rate falls to 21, 500 disintegrations/minute after 75 minutes. The $\mathrm{t}_{1 / 2}$ for ${ }^{41} \mathrm{Ar}$ is:
(a)90 minutes
(b)110 minutes
(c)180 minutes
(d)220 minutes
Answer
SELF-PRACTICE — the source book printed no answer.
Nothing is invented here, so this question has no answer on record.