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Nuclear Physics

Most commonly known for its applications in nuclear energy and nuclear weapons, Nuclear Physics also has applications in medicine and archaeology. This category is for questions about the branch of physics that deals with the study of the forces, reactions, and internal structures of atomic nuclei, Nuclear Physics.

3,164 Questions

The nuclei of carbon-12 and carbon -13?

612C contains 6 protons and 6 neutrons, while 613C contains 6 protons and 7 neutrons. Both are stable, with 612C accounting for 98.89% of the natural carbon in the environment, and with 613C accounting for 1.11% of the natural carbon in the environment.

What is the nuclear reaction for the alpha decay of oxygen-15?

Oxygen-15 does not decay by alpha decay. It decays by beta+ decay to Nitrogen-15, giving off a positron and an electron neutrino.

715O --> (beta+)--> (t1/2 = 122.24 seconds) --> 615N + e+ + ve

What isdifference nuclear fission and nuclear fission?

The difference between Fusion and Fission is that Fission is easier to do and produces more energy than fusion reactions. However fission can be dangerous and is used in Nuclear reactors. Fusion however is safer and produces less energy but safely. It is quite difficult to cause a Fusion reaction however.

What is the charge of a carbon 14 nuclide?

The charge of any nuclide is independent of its atomic mass number. It depends entirely on the electron to proton ratio.

614C simply has 6 protons and 8 neutrons. There is nothing to say how many electrons there are. The usual case, in a non-ionized atom, would be 6. If there were, for instance, one electron missing, the correct symbol would be 614C1+.

What is a nucleus that emits energy and particles spontaneously?

Any radioactive element gives off subatomic particles, and these particles carry considerable energy. That is the definition of radioactivity. Examples of radioactive elements include uranium, plutonium, polonium, radium, and many more.

Is radioactive decay affected by external conditions?

In reality, and what you will be taught in a standard physics textbook, is that radioactive decay is not affected by external conditions.

However, theoretically, if the temperature is around 100GeV (giga electron volts), then the weak force will be unified with the strong force and the electromagnetic forces, meaning it will no longer be "weak" and the rate of decay will thus increase dramatically.

What is half of a radioactive isotope?

Half of a radioactive isotope is an atom that would have half of the atomic number of the radioactive isotope. In the case of radium-88 (88Ra), half of the radioactive isotope would be ruthenium-44 (44Ru). This assumes that the protons do not break down and that none are lost to additional reactions with other elements or compounds. Electrons can be lost along the radioactive chain, resulting in an ion of ruthenium rather than an electrically neutral atom.

How long is three half lives?

It is 5 times the time of one half-life. Please note that different isotopes have half-lives that vary from a tiny fraction of a second to billions of years, so you can't know how long this is in days, or years, or whatever, until you know what isotope you are talking about.

What does the weak nuclear force act on?

The weak force is the one that allows a quark to turn into a different flavor of quark, thus allowing a neutron to transform into a proton, or a proton to transform into a neutron. In the case of the neutron, one of its down quarks change to an up quark, emitting a W- boson in the process. The boson is itself unstable and rapidly decays into an electron and an electron antineutrino. In the case of the proton, one of its up quarks changes into a down quark, and a W- boson appears briefly, then transforms into a positron and an electron neutrino. If any of this sound familiar, it is because this is the mechanism behind beta decay. There are two kinds of beta decay (beta plus and beta minus), and you can review them and related material by using the links below to related questions.

What is the equation for the alpha decay of nobelium?

There are several isotopes of nobelium, and of those, several decay by alpha decay. I picked the one with the longest known half-life, nobelium-259, at 58 minutes. I did not consider nobelium-261, or -263, which are expected to be longer, because they have yet to be synthesized in the lab.

102259No --> 75% alpha --> 100255Fm + 24He2+

Nobelium-259 also decays by electron capture / beta+ with an incidence of about 25%. The NNDC database also states a spontaneous fission rate of less than 10%. That does not add up, but that's what the database says. I think the ambiguity is due to the relatively short half-life of the element and the difficulty in synthesizing and observing it.

Which of the three radioactive particles can go through matter the best?

Alpha particles can be stopped by a piece of paper, beta particles can penetrate through skin but can be stopped by a sheet of aluminum, while gamma rays are the most penetrating and can pass through most materials, requiring dense materials like lead or concrete to be stopped.

What is the next biggest thing after atoms?

With atoms, you can make molecules. For example, two hydrogen atoms, H, will rapidly combine to form one hydrogen molecule, H2. Add one oxygen atom, and it makes water, H2O.

What is the equation for the radioactive decay reaction electron capture by rubidium 82?

The equation for the radioactive decay reaction electron capture by rubidium 82 is:

82Rb + e⁻ → 82Kr + ν

where 82Rb is the radioactive isotope of rubidium, e⁻ represents an electron, 82Kr is the resulting isotope of krypton, and ν denotes an electron neutrino.

What is a fusion reaction also known as?

Since they do not exist yet I do not believe they have any other names.

Fusion does exist in nature so a sun or star could be considered a fusion reactor.

Why are beta particles different from cathode ray particles?

Beta particles can be electrons (beta-) or positrons (beta+), along with electron antineutrinos (beta-) or electron neutrinos (beta+). Cathode ray particles are just electrons.

Since neutrinos have no charge, they do not interact well with matter. As a result, the electrons from beta- decay are nearly indistinguishable from the electrons in cathode rays, with the possible exception of their velocity.

Is uranium-235 an alpha particle?

No. 92235U is a radioisotope with 92 protons, 143 neutrons, and (in a non-ionic, neutral state) 92 electrons. An alpha particle, on the other hand, is a helium nucleus, 24He2+ with 2 protons, 2 neutrons, and no electrons.

It happens that 92235U decays by alpha decay to 90231Th with a half-life of 7.04 x 109 years, but this does not means that it is an alpha particle, it means that it emits an alpha particle. It also decays by spontaneous fission with a probability of 7 x 10-9%. It primary value, however, is that it is fissile, meaning that if it absorbs a thermal neutron, it will undergo fission, generating more neutrons, two new isotopes, and energy.

After how many days 1-4 of the original amount of gold 198 will remain?

After 4 days, only 1/16 of the original amount of gold (198/16 = 12.375) will remain.

What is beta decay of thorium 234?

In beta decay of thorium-234, a neutron in the nucleus of thorium-234 is transformed into a proton, releasing an electron (beta particle) and an antineutrino. This process converts the thorium-234 nucleus into protactinium-234.

Where would you find a nuclear fusion reaction occurring?

Nuclear fusion reactions occur in the core of stars, including the Sun, where high pressure and temperature conditions allow hydrogen atoms to combine and release a tremendous amount of energy. Scientists are also working on creating controlled nuclear fusion in experimental reactors on Earth as a potential source of sustainable energy.

Is alpha particles heavier than beta particles?

Yes. A beta particle is just an electron, while an alpha particle is effectively a helium nucleus - two protons plus two neutrons.

Protons (and neutrons) are each about 2000 times heavier than an electron.

Therefore, an alpha particle is about 8000 times heavier than a beta particle.

How does fission and fusion differ from alpha and beta decay?

Beta- decay involves the conversion of a neutron into a proton and the release of an electron and an electron antineutrino.

Beta+ decay involves the conversion of a proton into a neutron, sometimes by K capture, and the release of a positron and an electron neutrino.

Fusion involves the combining of two relatively light nuclei into one.

Alpha decay and fission are somewhat related...

Fission involves the separation of one relatively heavy nucleus into two or more.

Alpha decay is fission wherein the split off nucleus is a helium nucleus.

Any of these processes can leave the nucleus or the electron cloud in an excited state. When it comes back down to ground state, a gamma (nucleus) or x-ray (electron cloud) photon is emitted. This usually occurs nearly instantaneously, within about 1 x 10-12 seconds, but sometimes, in what we call a metastable state, this return to ground state is delayed, occasionally for a long time.

Why does plutonium have a less mass then uranium?

Plutonium generally has a lower atomic mass compared to uranium because it has fewer protons and neutrons in its nucleus. Plutonium isotopes tend to have a smaller number of nucleons overall compared to most uranium isotopes, resulting in a lower atomic mass.

What is the LD50 of strontium-90?

The LD50/50 (50% mortality in 50 days) for strontium-90 in rats is estimated to be around 2.5 to 3 microcuries per gram of body mass. I do not know if that translates linearly to humans.

Why does Carbon-14's half-life limit what can be dated by the radiocarbon method when using C14?

After about 10 half-lives, or about 60,000 years, the number of atoms of carbon-14 remaining in a sample is so small that the possible contamination of the sample from atmospheric sources while it was simply lying in wait increases the uncertainty beyond an acceptable level.

Additionally, the levels of carbon-14 have varied over the years due to varying levels of cosmic rays and other climate related changes. As a result, it is necessary to fit the decay curve into the known history and compare it with calibration sources that were dated using other methods. We don't have good calibration sources beyond 60,000 years.