Question 333: Atoms & Nuclei

Question

Starting with a sample of pure $${}^{66}Cu,{7 \over 8}$$ of it decays into $$Zn$$ in $$15$$ minutes. The corresponding half life is

Accepted Answer

$${7 \over 8}$$ of $$Cu$$ decays in $$15$$ minutes.
$$	herefore$$ $$Cu$$ undecayed $$ = N = 1 - {7 \over 8} = {1 \over 8} = {\left( {{1 \over 2}} ight)^3}$$
$$	herefore$$ No. of half lifes $$=3$$
$$n = {t \over T}$$ or $$3 = {{15} \over T}$$
$$ \Rightarrow T = $$ half life  period $$ = {{15} \over 3} = 5\,\,$$ minutes

Answer

$$15$$ minutes

Answer

$$10$$ minutes

Answer

$$7{1 \over 2}$$ minutes

Answer

$$5$$ minutes

Atoms & Nuclei

Starting with a sample of pure ${}^{66}Cu,{7 \over 8} of it decays into Zn in 15$ minutes. The corresponding half life is

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