A 100.0 gram sample of Polonium-210 is contained for 552 days. How many half-lives occur during this period of time, if the half-life is 138 days?

Respuesta :

Answer:

4 half-lives will occur during this period of time.

Explanation:

Formula used :

[tex]a_o=a\times e^{-\lambda t}[/tex]

[tex]\lambda =\frac{0.693}{t_{1/2}}[/tex]

[tex]a=\frac{a_o}{2^n}[/tex]

where,

a = amount of reactant left after n-half lives and time t

[tex]a_o[/tex] = Initial amount of the reactant.

[tex]\lambda = [/tex] decay constant

[tex]t_{1\2}[/tex] = half life of an isotope

n = number of half lives

We have :

[tex]a_o=100.0 g[/tex]

a = ?

t = 552 days

[tex]t_{1/2}=138 days[/tex]

[tex]a=100.0 g\times e^{-\frac{0.693}{138}\times 552}[/tex]

[tex]a=6.254 g[/tex]

[tex]6.254 g=\frac{100.0 g}{2^n}[/tex]

[tex]2^n=\frac{100.0 g}{6.254 g}[/tex]

n = 4

4 half-lives will occur during this period of time.