Question

Radio active carbon $C^{14}$ in a wood sample, decays with a half life of 5700 years. The fraction of the radio active carbon $C^{14}$, that remains after a decay period of $17,100$ years is :

• A. $1/4$
• B. $3/4$
• C. $1/8$
• D. $7/8$

Answer 1

The correct option is C $1/8$

$t_{1/2}=5700yrs$

Decay time $=17100yrs$

$=3\times 5700yrs$

$=3t_{1/2}$

Therefore, the amount left should be $(\frac{1}{2}{)}^3$ of initial amount.