Nuclear Physics

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

The electron has a neglible mass and a charge of minus 1.602 x 10-19 Coulombs.

We do have nuclear energy now, about 20 percent of total electricity in the US. It can only be used to generate electricity, so it does not cause any change in the way we use energy resources, other than using somewhat less fossil fuels.

No, an alpha particle is not identical to an electron. An alpha particle is a helium-4 nucleus, and it's composed of a pair of protons and a pair of neutrons fused together. It several thousand times the mass of an electron, and has twice its charge with an opposite sign (+2). An electron is that little negatively charged (-1) elementary particle that we find whizzing around atoms. You'll find a pair of related questions linked below.

Because only the isotope 235U is fissionable with thermal neutrons and also is good for nuclear weapons.

This is because normal uranium in the Earth is 0.7 % 235U and 99.3 % 238U. The 235U needs to be enriched to 4 % or greater in order to be effective as a fissile material (fission with neutrons producing fission and more neutrons that can continue the reaction) reaction. Power plants run around 4 % to 5 %; but CANDU type reactors work with natural uranium. Weapons run +99 %. Small high capacity reactors, such as on a submarine, run around 20 %.

1. Uranium must be refined to obtain "nuclear grade" uranium.

2. The enrichment in the isotope 235U depends on the type of the nuclear reactor; some reactors (as CANDU) work with natural uranium.

Gamma decay does not change the neutron-to-proton ratio for a nucleus. Gamma decay involves the emission of gamma rays, which are high-energy photons, without changing the composition of the nucleus.