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>
If an object has a higher density than the fluid it is in (fluid can mean liquid or gas), it will sink. If it has a lower density, it will float. Density is determined by an object's mass and volume. If two objects take up the same volume, but have one has more mass, then it also has a higher density.
Radioactive atoms are nuclei that can under go disintegration to emit either an alpha particle, beta particle or gamma radiation. The process could be spontaneous or stimulated.
When a radioactive atom R 88 210 emits alpha particle, it would produce an element with atomic number 86 and mass number 206 i.e X 86 206. An alpha particle is usually a helium nucleus.
