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3 years ago

The isotope Np-238 has a half life of 2.0 days if 96 grams of it were present on Monday how much will remain six days later

Chemistry

1 answer:

Neporo4naja [7]3 years ago

4 0

Answer:

12 grams

Explanation:

For any radioactive substance

the amount of substance left after n half life is given by = $x/2^n$

where x the original amount of substance.

____________________________________________

Half life of isotope Np-238 = 2 days

total no of days = 6

no of half life =total no of days/Half life of isotope Np-238 = 6/2 = 3

thus,

for our problem n = 3

initial amount of Np-238 = 96 grams

thus,

the amount of substance left after 3 half life = 96/2^3 = 96/8 = 12 grams.

Thus, 12 grams will be left after six days.

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How many miles of C atoms are present in a sample of 3.85x1024 C atoms?

alekssr [168]

Answer:
number of moles = 6.393 moles

Explanation:
One mole of any substance contains Avogadro's number (6.022 * 10^23) of atoms.
Therefore, to know the number of moles that contain 3.85 * 10^24 atoms, all we have to do is cross multiplication as follows:
1 mole ......................> 6.022 * 10^23
?? moles ..................> 3.85 * 10^24
number of moles = (3.85 * 10^24 *1) / (6.022 * 10^23)
number of moles = 6.393 moles

Hope this helps :)

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3 years ago

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nikklg [1K]

Explanation:

Entropy -

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cooling process , reduces the randomness , hence , entropy decreases .

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4 years ago

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aleksley [76]

Answer:

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3 years ago

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eimsori [14]

Answer:

Explanation:

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3 years ago