Identify the nuclide produced when plutonium-239 decays by alpha emission: 239 94pu→42he + ? express your answer as an isotope u
sing prescripts. 235 92u submithintsmy answersgive upreview part incorrect; try again; 4 attempts remaining part b identify the nuclide produced when thorium-234 decays by beta emission: 234 90th→ 0−1e + ? express your answer as an isotope using prescripts. submithintsmy answersgive upreview part part c identify the nuclide produced when fluorine-18 decays by positron emission: 18 9f→01e + ? express your answer as an isotope using prescripts. submithintsmy answersgive upreview part part d identify the nuclide produced when thallium-201 decays by electron capture: 201 81tl+ 0−1e→00γ + ? express your answer as an isotope using prescripts.
<span>Since this is an alpha emission the atomic number
of the daughter nucleus decreases by 2 while mass number decreases by 4 compared to
parent atom. Since parent atom has 94 as atomic number the daughter atom should
have </span>94 - 2 = 92 as atomic number<span> <span>and </span></span>239 - 4 = 235 as mass
number. <span>
</span></span>₉₄²³⁹Pu → ₂⁴He + ₉₂²³⁵U<span>
2. </span><span>Answer is </span>₉₁²³⁴Pa<span>
</span><span>Since this is a beta emission, a neutron is
converted into a proton while emitting an electron. Hence atomic number
increases by 1 compared to mass number but mass number remains as same. Hence,
the </span>atomic number of the
daughter atom<span> <span>should be </span></span>90 + 1 = 91<span> <span>which belongs to </span></span>Pa<span>. But the </span>mass number is same
as 234.<span>
</span>₉₀²³⁴Th → ₋₁⁰e + ₉₁²³⁴Pa<span> </span><span> 3.<span> <span>Answer is </span></span></span>₈¹⁸O<span>
</span><span>Since this is a positron emission, a proton is converted into a neutron
while emitting an positron. Hence atomic number decreases by 1 compared to mass
number but mass number remains as same. Hence, the </span>atomic number of the
daughter atom<span> should be </span>9- 1
= 8 <span>which belong to </span>O<span>. But the </span>mass
number is same as 18.<span>
</span>₉¹⁸F → ₊₁⁰e + ₈¹⁸O<span>
4. </span>Answer is₈₀²⁰¹Hg<span>
</span><span>This is an </span><span>electron capture
decay. </span>A<span> proton is converted into a neutron by emitting
a gamma ray. In this process </span>mass number remains
as same<span> <span>as parent atom which is </span></span>201<span>, but the </span>atomic number is
decreased by 1<span> <span>than parent atom. Hence atomic number of
daughter nucleus is 81 -1 = </span></span>80 <span>which belongs to </span>Hg.<span> </span><span> </span>₈₁²⁰¹Tl + ₋₁⁰e → ₀⁰γ + ₈₀<span>²⁰¹Hg</span>
The same number of each element present before the reaction takes place must also be present on the product side of the equation. Coefficients are placed in front of a chemical formula to show the number of moles of that substances that are necessary for the reaction to occur.
