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Umnica [9.8K]
3 years ago
15

A sample of a certain isotope has an initial activity of 40,000 cpm. After 24.8 days, the activity is 2500 cpm. What is the half

life of the isotope?
Chemistry
1 answer:
Hitman42 [59]3 years ago
5 0

Answer:

6.2 days

Explanation:

initial activity = 40,000 cpm

one half-life = 20,000 cpm

two half-lives = 10,000 cpm

three half-lives= 5,000 cpm

four half-lives = 2500 cpm

24.8 days/4 half-lives = 6.2 days/ half-life

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What is the decay mode of radium-226?
inn [45]

Answer:

Radium-226 is a radioactive decay product in the uranium-238 decay series and is the precursor of radon-222. Radium-228 is a radioactive decay product in the thorium-232 decay series. Both isotopes give rise to many additional short-lived radionuclides, resulting in a wide spectrum of alpha, beta and gamma radiations.

6 0
3 years ago
After 1 min, three radioactive nuclei remain from an original sample of six. Is it valid to conclude that t₁/₂ equals 1 min? Is
Harrizon [31]

Three of them may have decayed more quickly or more slowly than they should have according to the likelihood at that particular moment. However, suppose we have a lot of radioactive new Clyde's, say six times 10 to the 12, and we have three times 10 to the 12 in a minute. The rate may then be averaged out because there are a sufficient number of radioactive new Clyde's. Furthermore, we can say with confidence that the half life is one minute.

<h3>What is radioactivity?</h3>

Radioactivity, as its name suggests, is the act of generating radiation without any external cause. An atomic nucleus that is unstable for whatever reason does this by "wanting" to give up some energy in order to change its configuration to one that is more stable. Modern physics spent a lot of time in the first half of the 20th century figuring out why this occurs, which led to a pretty solid understanding of nuclear decay by 1960. A nucleus with too many neutrons will produce a negative beta particle, which will convert one of the neutrons into a proton. A nucleus with too many protons will emit positrons, which are positively charged electrons that turn protons into neutrons.

To know more about radioactivity:

brainly.com/question/1770619

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7 0
2 years ago
CH2OHCH2OH is a general example of: an ethyl alcohol a methyl alcohol a polyhydroxyl alcohol an organic acid
RoseWind [281]

CH2OHCH2OH is a general example of a polyhydroxyl alcohol. A polyhydroxyl alchol is one in which there are two hydroxyl groups present in the substance. The –OH group attached to both the carbon atoms.

4 0
3 years ago
Read 2 more answers
Balance the following equation:<br> K+ H2O + H2 + KOH
alex41 [277]

Answer:

2K + 2H2O → H2 + 2KOH

Explanation:

Find how many atoms you have on both sides then add 2 to both sides.

Reactant:       Products:

K: 1+1=2                K: 1+1=2

H: 2+2=4             H: 3+1=4

O: 1+1=2                O: 1+1=2

Therefore it is balanced. Hope this helps

6 0
3 years ago
A chemist prepares a solution of magnesium chloride MgCl2 by measuring out 49.mg of MgCl2 into a 100.mL volumetric flask and fil
Flura [38]

Answer:  Molarity of Cl^- anions in the chemist's solution is 0.0104 M

Explanation:

Molarity : It is defined as the number of moles of solute present per liter of the solution.

Formula used :

Molarity=\frac{n\times 1000}{V_s}

where,

n= moles of solute

Moles=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{0.049g}{95g/mol}=5.2\times 10^{-4}moles  

V_s = volume of solution in ml = 100 ml

Now put all the given values in the formula of molarity, we get

Molarity=\frac{5.2\times 10^{-4}moles\times 1000}{100ml}=5.2\times 10^{-3}mole/L

Therefore, the molarity of solution will be 5.2\times 10^{-3}mole/L

MgCl_2\rightarrow Mg^{2+}+2Cl^-

As 1 mole of MgCl_2 gives 2 moles of Cl^-

Thus 5.2\times 10^{-3}  moles of MgCl_2 gives =\frac{2}{1}\times 5.2\times 10^{-3}=0.0104

Thus the molarity of Cl^- anions in the chemist's solution is 0.0104 M

6 0
3 years ago
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