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3 years ago

After two half-lives, how much of the original material has decayed? 25 percent 50 percent 75 percent 100 percent

Chemistry

1 answer:

RideAnS [48]3 years ago

8 0

The original material has decayed 75%

<h3>Further explanation</h3>

Given

two half-life

Required

The decayed sample

Solution

General formulas used in decay:

$\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}$

t = duration of decay

t 1/2 = half-life

N₀ = the number of initial radioactive atoms

Nt = the number of radioactive atoms left after decaying during T time

t = 2 x t 1/2

Input the value :

$\tt \dfrac{Nt}{No}=\dfrac{1}{2}^2=\dfrac{1}{4}=25\%$

The amount of Nt = 25% No

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3 years ago

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4 years ago

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The balanced chemical reaction is :

<em />

Given data :

Mass of sodium = 10.0 g

Number of moles of Na -

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