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Archy [21]
3 years ago
7

Iodine-131 has a half-life of 8 days. How long would it take for the number of unstable nuclei in the sample to be reduced from

1,000 to 125?
Chemistry
1 answer:
Svet_ta [14]3 years ago
7 0

Answer:

After one-half life: 16 mg

After 2-half lives: 8 mg

After 3-half lives: 4 mg

After 4-half lives: 2 mg

After 5-half lives: 1 mg

(5 half-lives) x (8 days/half-life) = 40 days  

or doing it the mathematical way:  Let z be the number of days to be found:

1 mg = 32 mg x (1/2)^(z / 8 days)  

1/32 = (1/2)^(z / 8 days)  

log (1/32) = (z / 8 days) x log (1/2)  

z / 8 days = log (1/32) / log (1/2)

z = 8 days x log (1/32) / log (1/2) = 40 days

Explanation:

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Ne4ueva [31]

Answer:

Acid Uses

Organic acids

Citric acid As a preservative for food As a flavouring agent

Ascorbic acid (also called vitamin C) In the treatment of bone marrow and scurvy diseases

Acetic acid Added to pickles to make them sour

Explanation:

7 0
2 years ago
What is the relationship between chemical equilibrium and the rates of forward and reverse reaction?
Nataly_w [17]

Answer:

c

Explanation:

the rate of a forward process must be exactly balanced by the rate of the reverse process.

3 0
3 years ago
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What is the PH of a 1.3×(10)^-9 M HBr solution?
olga nikolaevna [1]

pH solution = 8.89

<h3>Further explanation</h3>

Given

The concentration of HBr solution = 1.3 x 10⁻⁹ M

Required

the pH

Solution

HBr = strong acid

General formula for strong acid :

[H⁺]= a . M

a = amount of H⁺

M = molarity of solution

HBr⇒H⁺ + Br⁻⇒ amount of H⁺ = 1 so a=1

Input the value :

[H⁺] = 1 x  1.3 x 10⁻⁹

[H⁺] = 1.3 x 10⁻⁹

pH = - log [H⁺]

pH = 9 - log 1.3

pH = 8.89

7 0
2 years ago
What is the electron (subshell) configurations for 15P
prisoha [69]
58 ce is the correct answer!
6 0
2 years ago
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Please help need answer fast ???
Alika [10]

Answer: 1.33x10^-22g

Explanation:Please see attachment for explanation

6 0
3 years ago
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