Question

The half - life of a radioisotope is four hours. If the initial mass of the isotope was 200 g, the mass remaining after 24 hours undecayed is

• A. $1.042 \,g$
• B. $4.167 \,g$
• C. $3.125\, g$
• D. $2.084 \,g$

Answer 1

Answer: (C)

$3.125\, g$

Answer 2

$2^{6} = \frac{200}{a-x}$ $\left(a - x\right) = 3.125 \,gm$