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KIM [24]
2 years ago
15

You have 500,000 atoms of a radioactive substance. After 2 half-lives have past, how many atoms remain?

Chemistry
2 answers:
Aleonysh [2.5K]2 years ago
3 0

Answer:

125000

Explanation:

Because it is halved and halved again.

solong [7]2 years ago
3 0
Half life - when half of the radioactive substance has become stable

500,000/2 = 250,000 remaining after the first half life

250,000/2 = 125,000 remaining after the second


Or alternatively 1/4 x 500,000 = 125,000
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Medicine and urine are seperated by which method?​
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Answer:

Screening for the presence of drugs in serum and urine using different separation modes of capillary electrophoresis. The most common mode is capillary zone electrophoresis (CZE), in which charged analytes migrate in a buffer under the influence of an electric field.

Explanation:

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3 years ago
Iodine-131 is administered orally in the form of NaI(aq) as a treatment for thyroid cancer. The half-life of iodine-131 is 8.04
evablogger [386]

Answer:

16.6 mg

Explanation:

Step 1: Calculate the rate constant (k) for Iodine-131 decay

We know the half-life is t1/2 = 8.04 day. We can calculate the rate constant using the following expression.

k = ln2 / t1/2 = ln2 / 8.04 day = 0.0862 day⁻¹

Step 2: Calculate the mass of iodine after 8.52 days

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ln I = ln I₀ - k × t

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SIZIF [17.4K]

A combustion reaction is a reaction that reacts in the presence of oxygen molecules. Methane will release -3115 kJ/mol of heat.

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A combustion reaction includes the reaction between the chemical reactant and oxygen molecule to produce the product. The combustion reaction between methane and oxygen is given as:

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