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m_a_m_a [10]
3 years ago
8

After 11.5 days, 12.5% of a sample of radon-222 that originally weighed 42g remains. What is the half-life of this isotope?

Chemistry
1 answer:
Bond [772]3 years ago
5 0
Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value.  The equation to describe the decay is
Nt=N0(1/2) ^{t/t(1/2)}  where N0 is the initial quantity, Nt is the remaining quantity after time t, t1/2 is the half-time.  So work out the equation, t1/2 = t (-ln2)/ln(Nt/N0) = 11.5*(-ln2)/ln(12.5/100) = 3.83 days
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And your unbalanced and balanced equations are correct.

(sorry I went on a tangent with the diatomic rules hopefully it will help you in the future though) 
8 0
2 years ago
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yanalaym [24]

Answer : The correct option is, Malleable, shiny, and able to conduct heat or electricity.

Explanation:

Metals : Metals are the elements which can easily loose electrons and forms cations.

Properties of metals :

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Non-metals : Non-metals are the elements which can easily gain electrons and form an anion.

Properties of non-metals :

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8 0
2 years ago
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fenix001 [56]
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Hope this answers the question.
8 0
3 years ago
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grin007 [14]

Answer:

<h3>Right answer is: ( a) chalk powder remains suspended in water.</h3>

Explanation:

Filtration is the technique used to separate suspended solute particles from a solution . The chalk powder remains suspended in the solution and can easily be filtered through a filter paper , the chalk powder can be collected on the filter paper and clear solvent is collected as the filtrate.

4 0
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