Question

$C^{14}$ has half life 5700 years. At the end of 11400 years, the actual amount left is.

• A. 0.5 of original amount
• B. 0.25 of original amount
• C. 0.125 of original amount
• D. 0.0625 of original amount

Answer 1

Answer: (B)

0.25 of original amount

Answer 2

$N = N_{0} \times \left( \frac{1}{2} \right)^{11400/5700} = N_{0}\left( \frac{1}{2} \right)^{2}$ $= 0.25N_{0}$.