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Free_Kalibri [48]
3 years ago
6

A sample of polonium-210 has an initial mass of 321 milligrams (mg). If the half-life of polonium-210 is 138 days, how many mg o

f the sample remains after 1000 hours?
Chemistry
1 answer:
raketka [301]3 years ago
3 0

Hey there!

A half-life means after a certain amount of time, half of that substance will have decayed after that time.

An equation for exponential decay is the following:

y = a(1 - b)ⁿ

Where a is the original amount, b is the rate of decay, and n is time.

1000 is about 0.3 of a half life, 1000 divided by 138 days (3312 hours) is approximately 0.3.

Let's plug in values to that equation:

y = 321(1 - 0.5)^(0.3)

Simplify.

y = 260.73

There will be 260.73mg of polonium-210 remaining after 1000 hours.

Hope this helps!

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Who established atomic numbers as the basis for organizing the periodic table?
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Answer:

Henry Moseley.

Explanation:

Hello,

Henry Moseley's work stated that it is better to organize the periodic table in the light of the atomic number (which accounts for the amount of protons and electrons) instead of the atomic mass, because atomic numbers are not arbitrarily assigned as long as they have the aforesaid physical basis.

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Identify all statements that accurately describe the structure of the pyruvate dehydrogenase ( PDH ) complex.
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Answer:

The statements that correctly describes pyruvate dehydrogenase includes:

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Explanation:

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The work function of an element is the energy required to remove an electron from the surface of the solid. The work function fo
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λ = 2.38 × 10^(-7) m

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