Question

16 gm sample of a radioactive element is taken from Bombay to Delhi in 2 hour and it was found that 1 gm of the element remained (undisintegrated). Half life of the element is.

• A. 2 hour
• B. 1 hour
• C. $\frac{1}{2}hour$
• D. $\frac{1}{4}hour$

Answer 1

Answer: (C)

$\frac{1}{2}hour$

Answer 2

$N = N_{0}\left( \frac{1}{2} \right)^{t/T_{1/2}}$⇒ $1 = 16\left( \frac{1}{2} \right)^{\frac{2}{T_{1/2}}}$ ⇒ $T_{1/2} = \frac{1}{2}hour$