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svetlana [45]
3 years ago
12

The half- life of actinium-228 is 6.13 hours What amount of a 70 milliqram sample remains after 24.52 hours?

Chemistry
1 answer:
Usimov [2.4K]3 years ago
4 0

Answer:

4.375 milligram

Explanation:

Applying,

A = A'(2ᵃ/ⁿ)............. Equation 1

Where A = original amount of actinium-228, A' = amount of actinium-228 left after decay, a = Total time, n = half life

make A' the subject of the equation

A' = A/(2ᵃ/ⁿ)........... Equation 2

From the question,

Given: A = 70 milligram, a = 24.52 hours, n = 6.13 hours

Substitute these values into equation 2

A' = 70/(2²⁴°⁵²/⁶°¹³)

A' = 70/(2⁴)

A' = 70/16

A' = 4.375 milligram

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How is it possible to predict the type of bond that is likely to be found in a substance? what types of atoms generally form ion
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3 years ago
Calculate the ratio of the velocity of helium atoms to the velocity of neon atoms at the same temperature.
o-na [289]

Answer:

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Explanation:

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Where R is gas constant (8.314 kgm²/s²molK); T is temperature and M is molar mass of the gas (4x10⁻³kg/mol for helium and 20,18x10⁻³ kg/mol for neon). Thus:

vHe = √3×8.314 kgm²/s²molK×T / √4x10⁻³kg/mol

vNe = √3×8.314 kgm²/s²molK×T / √20.18x10⁻³kg/mol

The ratio is:

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<em>vHe / vNe = 2.24</em>

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I hope it helps!

8 0
3 years ago
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