Answer:
The answer is given below in the picture
Explanation:please check it
Answer:
37S
Explanation:
Radioactivity is the spontaneous emission of particles and / or electromagnetic radiation by unstable atomic nuclei leading to their disintegration.
We have two main types of radioactivity: radioactive decay and artificial transmutation.
In radioactive decay ( natural radioactivity ), a naturally occurring radioactive element like Uranium-238 disintegrates or decays into more stable isotopes with the emission of particles and/or radiation.
23892U = 23490Th + 42He
Artificial transmutation is the collision of two particles where one particle captures the other used to bombard it. There is subsequent production of isotopes similar or different from the bombarded particle. Neutrons, alpha particles ( helium nucleus ), electrons, protons can be used to bombard elements.
147N + 42He = 178O + 11P
For the above question which is artificial transmutation, the reaction equation is
4018Ar + 10n = 3716S + 42He
So, the neutron capture by Argon-40 will produce a radioisotope Sulphur-37 with the emission of an alpha particle.
The answer is <span>(3) 3 × 12.4 hours
</span>
To calculate this, we will use two equations:
![(1/2) ^{n} =x](https://tex.z-dn.net/?f=%281%2F2%29%20%5E%7Bn%7D%20%3Dx)
![t_{1/2} = \frac{t}{n}](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%20%3D%20%5Cfrac%7Bt%7D%7Bn%7D%20)
where:
<span>n - number of half-lives
</span>x - remained amount of the sample, in decimals
<span>
![t_{1/2}](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%20)
- half-life length
</span>t - total time elapsed.
First, we have to calculate x and n. x is <span>remained amount of the sample, so if at the beginning were 16 grams of potassium-42, and now it remained 2 grams, then x is:
2 grams : x % = 16 grams : 100 %
x = 2 grams </span>× 100 percent ÷ 16 grams
x = 12.5% = 0.125
Thus:
<span>
![(1/2) ^{n} =x](https://tex.z-dn.net/?f=%281%2F2%29%20%5E%7Bn%7D%20%3Dx)
</span>
![(0.5) ^{n} =0.125](https://tex.z-dn.net/?f=%280.5%29%20%5E%7Bn%7D%20%3D0.125)
![n*log(0.5)=log(0.125)](https://tex.z-dn.net/?f=n%2Alog%280.5%29%3Dlog%280.125%29)
![n= \frac{log(0.5)}{log(0.125)}](https://tex.z-dn.net/?f=n%3D%20%5Cfrac%7Blog%280.5%29%7D%7Blog%280.125%29%7D%20)
![n=3](https://tex.z-dn.net/?f=n%3D3)
It is known that the half-life of potassium-42 is 12.36 ≈ 12.4 hours.
Thus:
<span>
![t_{1/2} = 12.4](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%20%3D%2012.4%20)
</span><span>
![t_{1/2} *n = t](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%20%2An%20%3D%20t%20)
</span>
![t= 12.4*3](https://tex.z-dn.net/?f=t%3D%2012.4%2A3%20)
Therefore, it must elapse 3 × 12.4 hours <span>before 16 grams of potassium-42 decays, leaving 2 grams of the original isotope</span>
The primary greenhouse gases are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. So, the correct answer among these options is water vapor, that is considered to be a greenhouse gas.
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