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Reika [66]
3 years ago
10

HELP ASAPPPP

Chemistry
1 answer:
Cloud [144]3 years ago
3 0

Answer:

13 years

Explanation:

From;

0.693/t1/2 = 2.303/t log (No/N)

Where;

t1/12 = half-life of Cobalt-60 = 5.3 years

t = time taken = the unknown

No = mass of radioactive material originally present = 5.2 g

N = mass of radioactive material at time t = 0.95 g

Substituting values;

0.693/5.3 = 2.303/t log (5.2/0.95)

0.131 = 2.303/t(0.738)

0.131 = 1.6996/t

t =  1.6996/0.131

t = 12.97 years

t = 13 years(to the nearest whole number)

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Answer:

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Explanation:

The number of atoms can be found with the following equation:

n = N*\eta_{H}

Where:

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η: is the number of moles of hydrogen

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First, we need to find the number of hydrogen moles. The number of moles of CH₄ is:

\eta_{CH_{4}} = \frac{m}{M}

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\eta_{H} = 2.06\: mol\: CH_{4}*4 \frac{mol\: H}{mol \: CH_{4}} = 8.24 mol

Hence, the number of hydrogen atoms is:

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Therefore, the number of hydrogen atoms is 4.96x10²⁴.

I hope it helps you!      

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