The key difference between Uranium 234 235 and 238 is that Uranium 234 contains 142 neutrons and Uranium 235 contains 143 neutrons, whereas Uranium 238 contains 146 neutrons.
Uranium is a heavy metal. It is an abundant source of energy that has been used for about 60 years. It provides nuclear fuel for the generation of electricity. Uranium metal has many isotopes depending on the number of neutrons in their atomic nuclei.
CONTENTS
1. Overview and Key Difference
2. What is Uranium 234
3. What is Uranium 235
4. What is Uranium 238
5. Side by Side Comparison – Uranium 234 vs 235 vs 238 in Tabular Form
6. Summary
What is Uranium 234?
Uranium 234 is an isotope of Uranium heavy metal, having 95 protons and 142 neutrons in the atomic nucleus. We can denote this isotope as 234U. It is a rare isotope having a natural abundance of around 0.0054%. This is because its half-life (246 000 years) is about 1/18 000 of Uranium 238 isotope. Therefore, we can observe uranium 234 in uranium ores as the decay product of uranium 238.
The primary path of producing uranium 234 is through nuclear decay, which involves uranium 238 (the parent isotope of uranium 234) emitting an alpha particle, resulting in thorium 234 followed by thorium 234 (has a short half-life) emitting a beta particle to form protactinium 234, which then tend to emit another beta particle forming uranium 234 nuclei.
We can isolate uranium 234 through the isotope separation method or via regular uranium enrichment method, but there is no sufficient demand for this isotope in chemistry, physics or engineering.
Apart from that, uranium 234 has a neutron-capture cross-section that is about 100 barns for thermal neutrons and about 700 barns for the resonance integral (the average neutrons having a range of intermediate energies). When we use uranium 234 in a nuclear reactor, we can observe that both uranium 234 and 238 tend to capture a neutron, followed by conversion into uranium 235 and plutonium 239, respectively. The conversion of uranium 234 into uranium 235 occurs at a greater rate than the conversion of uranium 238 to plutonium 239.
What is Uranium 235?
Uranium 235 is an isotope of uranium heavy metal, having 92 protons and 143 neutrons. When considering its natural abundance, it is about 0.72% making it abundant than uranium 234. This isotope is fissile, and it can sustain a fission chain reaction. Moreover, this is the only fissile isotope that occurs naturally as a primordial nuclide.
The half-life of this isotope is about 703.8 million years. This substance was discovered by Arthur Jeffery Dempster in 1935. Further, the fission cross-section for slow thermal neutrons is about 585 barns, and for fast neutrons, it is about 1 barn. Usually, almost all the neutron absorptions of this isotope result in fission, and a minority of it occurs in neutron capturing, which forms uranium 236.
What is Uranium 238?
Uranium 238 is an isotope of uranium, having 92 protons and 146 neutrons in the atomic nuclei. It is the most abundant isotope of uranium that occurs in nature. The relative abundance is about 99%. This isotope of uranium is not fissile. Therefore, it cannot sustain a chain reaction in a thermal-neutron reactor.
However, uranium 238 can be fissionable by fast neutrons. The reason why uranium 238 cannot sustain a chain reaction is that inelastic scattering reduces neutron energy where there is a probable one or more next-generation nuclei.
What is the Difference Between Uranium 234 235 and 238?
Uranium metal has many isotopes depending on the number of neutrons in their atomic nuclei. The key difference between Uranium 234 235 and 238 is that Uranium 234 contains 142 neutrons and Uranium 235 contains 143 neutrons, whereas Uranium 238 contains 146 neutrons.
Below is a list of differences between Uranium 234 235 and 238 in tabular form.
Summary – Uranium 234 vs 235 vs 238
Uranium is an important source of energy used in nuclear reactors for the generation of electricity. There are many different isotopes of uranium metal, which differ from each other according to the number of neutrons present in their atomic nuclei. The key difference between Uranium 234 235 and 238 is that Uranium 234 contains 142 neutrons and Uranium 235 contains 143 neutrons, whereas Uranium 238 contains 146 neutrons.
Reference:
1. “Uranium 234.” ScienceDirect Topics, Available here.
Image Courtesy:
1. “HEUraniumC” By US Department of Energy (Public Domain) via Commons Wikimedia
2. “Uranium03” By Forwardbias at the English-language Wikipedia (CC BY-SA 3.0) via Commons Wikimedia