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maks197457 [2]
3 years ago
11

Radium has a half-life of 1,620 years. In how many years will a 1 kg sample of radium decay and reduce to 0.125 kg of radium?

Chemistry
2 answers:
JulsSmile [24]3 years ago
8 0

Answer:

4860 years

Explanation:

From

N/No = (1/2)^t/t1/2

Where:

No= mass as time t=0

N= mass at time t

t= time

t1/2= half life

0.125/1 = (1/2)^t/1620

1/8 = (1/2)^t/1620

(1/2)^3= (1/2)^t/1620

3= t/1620

t= 3×1620

t= 4860 years

Tasya [4]3 years ago
7 0
We can calculate years by using the half-life equation. It is expressed as:

A = Ao e^-kt

<span>where A is the amount left at t years, Ao is the initial concentration, and k is a constant.

</span>From the half-life data, we can calculate for k.

1/2(Ao) = Ao e^-k(1620)
<span>k = 4.28 x 10^-4
</span>
0.125 = 1 e^-<span>4.28 x 10^-4 (</span>t)
t = 4259 years
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