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What is the equation for beta decay of carbon-14?
14C --> 14N + e-
What do you know about an isotope?
Isotopes have same atomic number. They have different mass numbers. Their physical properties are different.
Is the helium nucleus a byproduct of fission?
Yes, but only if the nuclear disintegration is alpha decay. Alpha decay is only one mode of radioactive decay, and in alpha decay, a helium-4 nucleus (the alpha particle) will appear. Beta decay (two types) and spontaneous fission are also modes of radioactive decay, and different particles appear in those events. Links are provided below to Related questions that will help you sort this out.
Are ultraviolet rays a particle of radioactive decay?
There are three main types of radioactive decay; called 'alpha radiation,' 'beta radiation,' and 'cluster decay.' For unstable atoms of heavier elements, the most common method of decay is alpha radiation, in which a group of protons and neutrons called an alpha particle is released. Alpha particles are essentially helium atoms; two protons and two neutrons. In beta radiation, a neutron (which is slightly more massive than a proton), loses some energy by spitting out a neutrino particle. This loss of energy turns the neutron into a proton. This means that when an atom undergoes beta decay, it's atomic mass number goes down, but it becomes a heavier element. The third main type is cluster decay. This is just like alpha radiation, except a larger number of protons and neutrons are emitted, or more than one alpha particle is emitted at once. Unstable atoms will undergo a series of decays during which they lose more and more energy and mass. This process is called a 'decay chain,' which ends when the atom finally reaches a stable number of protons and neutrons.
How would you write a nuclear equation for the most likely mode of decay for the unstable nuclide Kr-74?
Krypton-74 will most likely undergo beta decay, and the type of beta decay an observer will encounter will be beta plus decay. A proton in the nucleus will undergo a change and become a neutron, and a positron (e+) and an antineutrino (ve) will emerge from the reaction. The krypton-74 atom will transmute into a bromine-74 atom. The equation will look something like this: 3674Kr => 3574Br + e+ + ve
What two radioisotopes have the same decay mode?
jnb
Why there's not a formula for beta decay?
There certainly is a formula for beta decay. You just need to know the parent nuclide and the beta mode, beta- or beta+. See the related question below which answers this quite well.
What is the equation for beta decay of carbon-14?
14C --> 14N + e-
How can you say that radioactive decay is random unless you know that the nuclides are identical in the first place?
Radioactive decay is a random event. But we can assess it by statistical analysis of a large number of decay events across time for a given radionuclide. Standard stastical analysis ideas apply. The way we know that it is the radionuclide we specify is that we refine the sample chemically. Then we look at the decay mode. If it is a situation where there is particle emission, we can identify the particle and the energy it comes out at. If its electromagnetic, we can specify an energy associated with the photon. The mode of decay and the energy cast off are the ways we can insure our "count" of the decay events specifically targets the radionuclide we are investigating. That and the applied chemistry we specified to clean up the sample. We're good at this radioactive decay thing. We can count even a very few decay events, and do so accurately across time (though more is better). And because we've done our homework as regards type of decay and energies, we know what it is that is decaying, and how long it is taking to decay. We can arrive at a half-life for a given radionuclide. A link can be found below.
What element results if four protons and four neutrons are ejected from a plutonium nucleus?
The most common isotope of plutonium is Pu-239. Ejecting four protons and four neutrons would reduce the atomic number from 94 to 90 and the mass number from 239 to 231. Element #90 is Thorium, so the answer would be Thorium-231. However, that is not an actual decay mode for Pu-239. Pu-239 decays by emitting an alpha particle (two protons and two neutrons) to Uranium-235. U-235 can then further decay by emitting another alpha particle to form Th-231.
What does uranium become when it decays?
If we use uranium-238 as our starter isotope, what happens is that a nuclear decay event happens (in this case an alpha decay) and the U-238 transforms into a daughter isotope thorium (Th-234). The half-life of this transition is 4.5 billion years. Thorium-234 then undergoes a decay. And the process continues until a stable isotope is created as the last daughter of a decay chain. Note that there will be different half lives for the transition events, and the modes of decay will vary depending on what daughter is now the parent in the next decay event. Use the link below to see all the steps. The chart will show the whole chain including the half-life of isotope undergoing decay, the decay mode, and the daughter. Follow along using the keys and the process will reveal itself.
What particles has the same mass as an electron but a positive charge and is sometimes emitted from the nucleus during radioactive decay?
Protons are rarely emitted, but a decay mode called positron decay is very common. The positron is the antiparticle of the electron and is exactly the same mass as the electron. It has charge +e.
What do you know about an isotope?
Isotopes have same atomic number. They have different mass numbers. Their physical properties are different.
Is the helium nucleus a byproduct of fission?
Yes, but only if the nuclear disintegration is alpha decay. Alpha decay is only one mode of radioactive decay, and in alpha decay, a helium-4 nucleus (the alpha particle) will appear. Beta decay (two types) and spontaneous fission are also modes of radioactive decay, and different particles appear in those events. Links are provided below to Related questions that will help you sort this out.
Are ultraviolet rays a particle of radioactive decay?
There are three main types of radioactive decay; called 'alpha radiation,' 'beta radiation,' and 'cluster decay.' For unstable atoms of heavier elements, the most common method of decay is alpha radiation, in which a group of protons and neutrons called an alpha particle is released. Alpha particles are essentially helium atoms; two protons and two neutrons. In beta radiation, a neutron (which is slightly more massive than a proton), loses some energy by spitting out a neutrino particle. This loss of energy turns the neutron into a proton. This means that when an atom undergoes beta decay, it's atomic mass number goes down, but it becomes a heavier element. The third main type is cluster decay. This is just like alpha radiation, except a larger number of protons and neutrons are emitted, or more than one alpha particle is emitted at once. Unstable atoms will undergo a series of decays during which they lose more and more energy and mass. This process is called a 'decay chain,' which ends when the atom finally reaches a stable number of protons and neutrons.
How would you write a nuclear equation for the most likely mode of decay for the unstable nuclide Kr-74?
Krypton-74 will most likely undergo beta decay, and the type of beta decay an observer will encounter will be beta plus decay. A proton in the nucleus will undergo a change and become a neutron, and a positron (e+) and an antineutrino (ve) will emerge from the reaction. The krypton-74 atom will transmute into a bromine-74 atom. The equation will look something like this: 3674Kr => 3574Br + e+ + ve
What is it called when atomic nuclei spontaneously decay?
How the nucleus decays depends on the particular isotope. Some even decay in more than one way. One possibility is called alpha decay. In alpha decay, the nucleus emits an alpha particle (two protons and two neutrons). Another possibility is beta decay, in which one of the nucleons changes from a neutron to a proton or vice versa and the nucleus will throw out a beta particle. A beta particle can be either an electron or a positron. (To conserve lepton number, the nucleus also emits an electron antineutrino or an electron neutrino at the same time.) A third case is electron capture. In this, one of the inner electrons is absorbed by the nucleus, a proton changes to a neutron, and an electron neutrino is thrown off. Heavy nuclides can undergo spontaneous fission, in which the nucleus splits into two smaller daughter particles with mass numbers of roughly 90-100 and 130-140. Often some spare neutrons are also ejected at the same time. Cluster decay is yet another mode, which happens only for nuclei which also decay via alpha decay. It's similar to alpha decay except the emitted particle is not a helium-4 nucleus but a heavier element. It's distinguished from spontaneous fission by the fact in cluster decay, only certain nuclei are emitted and they're always well under 90 amu. Other rare decay modes are possible: proton emission, neutron emission, double proton emission, double beta decay, double electron capture, double positron emission, and electron capture with positron emission. Most of these names should be self-explanatory.
