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alisha [4.7K]
3 years ago
6

What percentage of radioactive substance remains after two half-lives

Chemistry
1 answer:
Ksju [112]3 years ago
3 0

Answer:

After 2 half-lives there will be 25% of the original isotope, and 75% of the decay product. After 3 half-lives there will be 12.5% of the original isotope, and 87.5% of the decay product. After 4 half-lives there will be 6.25% of the original isotope, and 93.75% of the decay product.

Explanation:

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Griffin was walking to school one day and found a old bone. He took it to a scientist friend of his, and after studying the bone
svet-max [94.6K]
This problem is easily solvable because radioactivity equations are common and well-established. The pseudo-first reaction is written below:

A = A₀(1/2)^(t/h)
where
A is the final amount
A₀ is the original amount
t is the time
h is the half life

5,000 = A₀(1/2)^(24,000/6,000)
Solving for A₀,
<em>A₀ = 80,000 atoms</em>
6 0
3 years ago
Why does a transformer require AC rather than DC?
LuckyWell [14K]
So if the voltage in case of DC<span> is same as </span>AC<span>, </span>then DC<span> current is larger </span>than AC<span>current. A </span>transformer<span> works on the principle of electromagnetic induction. It means that the change in magnetic flux across a coil induces a potential difference across the same.

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5 0
3 years ago
Read 2 more answers
Cellulose could provide an abundant and cheap form of glucose for humans. Why is cellulose not a source of nutrients for humans?
mojhsa [17]

Answer:

Option (c).

Explanation:

Cellulose is one of the most important carbohydrate of the plant that provide structural framework to the plant cells. Cellulose is made of the monomer of the glucose that are linked through the beta glycosidic linkages.

Although cellulose contains large number of glucose but it cannot be used as the nutrient source for humans. Humans and other vertebrates lacks the enzyme cellulase that is required for the digestion of cellulose. Cellulose cannot be broken down in the human body.

Thus, the correct answer is option (c).

8 0
3 years ago
Which statement best describes the liquid state of matter?
KonstantinChe [14]

Answer:D. It has indefinite shape but definite volume.

Explanation: The property and characteristics of liquids is it does not have a definite shape since it copies and conform on the shape of its container but it has a definite of fixed volume.

6 0
3 years ago
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Exactly 1.0 mol N2O4 is placed in an empty 1.0-L container and is allowed to reach equilibriumdescribed by the equation N2O4(g)↔
Vilka [71]

Answer : The correct option is, (C) 1.1

Solution :  Given,

Initial moles of N_2O_4 = 1.0 mole

Initial volume of solution = 1.0 L

First we have to calculate the concentration N_2O_4.

\text{Concentration of }N_2O_4=\frac{\text{Moles of }N_2O_4}{\text{Volume of solution}}

\text{Concentration of }N_2O_4=\frac{1.0moles}{1.0L}=1.0M

The given equilibrium reaction is,

                           N_2O_4(g)\rightleftharpoons 2NO_2(g)

Initially                      c                 0

At equilibrium   (c-c\alpha)           2c\alpha

The expression of K_c will be,

K_c=\frac{[NO_2]^2}{[N_2O_4]}

K_c=\frac{(2c\alpha)^2}{(c-c\alpha)}

where,

\alpha = degree of dissociation = 40 % = 0.4

Now put all the given values in the above expression, we get:

K_c=\frac{(2c\alpha)^2}{(c-c\alpha)}

K_c=\frac{(2\times 1\times 0.4)^2}{(1-1\times 0.4)}

K_c=1.066\aprrox 1.1

Therefore, the value of equilibrium constant for this reaction is, 1.1

4 0
2 years ago
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