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3 years ago

Radium-221 has a half-life of 30 sec. How long will it take for 96% of a sample to decay?

1 answer:

monitta3 years ago

3 0

We can calculate how long the decay by using the half-life equation. It is expressed as:

A = Ao e^-kt

where A is the amount left at t years, Ao is the initial concentration, and k is a constant.
From the half-life data, we can calculate for k.

1/2(Ao) = Ao e^-k(30)
k = 0.023

0.04Ao = Ao e^0.023(t)
t = 140 sec

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Answer : The volume of hydrogen gas at STP is 4550 L.

Explanation :

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

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$T_2$ = final temperature of gas at STP = $0^oC=273+0=273K$

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3 years ago

If kinetic energy increases does pressure decrease?

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kakasveta [241]

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Explanation:

During a neutralization reaction, an acid reacts with a base for producing the correspondent salt, and water.

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