The half-life of Carbon-14 is 5, 730 years. you find a sample where 1.5625% of the original Carbon-14 still remains how old is that sample ?

Respuesta :

Answer:

The sample is about 34380 years old.

Explanation:

The amount of Carbon-14 mass diminishes exponentially in time, whose model is described below:

[tex]\frac{m(t)}{m_{o}} = e^{-\frac{t}{\tau} }[/tex] (1)

[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (2)

Where:

[tex]m_{o}[/tex] - Initial mass, in grams.

[tex]m(t)[/tex] - Current mass, in grams.

[tex]t[/tex] - Time, in years.

[tex]\tau[/tex] - Time constant, in years.

[tex]t_{1/2}[/tex] - Half-life, in years.

If we know that [tex]\frac{m(t)}{m_{o}} = \frac{1.5625}{100}[/tex] and [tex]t_{1/2} = 5730\,yr[/tex], then the age of the sample is:

[tex]\tau = \frac{5730\,yr}{\ln 2}[/tex]

[tex]\tau = 8266.643\,yr[/tex]

[tex]t = - \tau \cdot \ln \frac{m(t)}{m_{o}}[/tex]

[tex]t = - (8266.643\,yr)\cdot \ln \frac{1.5625}{100}[/tex]

[tex]t \approx 34380.002\,yr[/tex]

The sample is about 34380 years old.