Question

A 100g sample of Carbon-14 has a half-life of 5 years. How much Carbon-14 is left after 10 years?

Answer 1

Answer: The amount of carbon-14 left after 10 years is 25 g

Explanation:

Formula used :

$a=\frac{a_o}{2^n}$

where,

a = amount of reactant left after n-half lives = ?

$a_o$ = Initial amount of the reactant = 100 g

n = number of half lives =$\frac{\text {given time}}{\text {half life}}=\frac{10}{5}=2$

Putting values in above equation, we get:

$a=\frac{100g}{2^2}$

$a=\frac{100g}{4}=25g$

Therefore, the amount of carbon-14 left after 10 years is 25 g