The first step is an alpha decay to (guess what!) uranium 235. You can probably take it from there.
Uranium-239 does NOT decay by alpha decay, it decays only by beta and gammadecay.
The daughter isotope of Pu-239 is U-235.
Nuclear decay is any spontaneous process where unstable nuclei release extra energy to arrive at a more stable state. Typical decay processes are Alpha, Beta, and Gamma. Some large unstable nuclei (e.g. Plutonium-240) can sometimes decay by spontaneous fission.Nuclear fission is a process where certain large nuclei (e.g. Uranium-235 & Plutonium-239) absorb a neutron and then split into two smaller nuclei and a few free neutrons. Some large unstable nuclei (e.g. Plutonium-240) don't need to be hit by a neutron to fission.Nuclear fusion is a process where small nuclei under unusual conditions of very high temperature and very high pressure combine to form larger nuclei.All three processes above are exothermic.In stars nuclear fusion stops at nickel and iron (further fusion past this would be endothermic). If all we had was the above processes then that would be where the periodic table ended (therefore there could not be nuclear fission as such heavy nuclei could not exist). However stars die, and some die so spectacularly we call them supernovas.When a supernova occurs, an intense shock wave blows all the outer layers of the star away at very high velocity. At these velocities nuclei collide so hard that normally impossible endothermic nuclear fusion reactions occur. The rest of the periodic table is filled here, including many transuranics not found naturally on earth (e.g. Americium, Californium, Berkelium).
For example americium-241 decay to neptunium-237 and americium-243 decay to neptunium-239.
Actually, they are biodegradeable, sort of. Radioactive materials do decay, or become weaker over time. Eventually they become inert, or non-radioactive. The problem is some radioactive isotopes take tens or even hundreds of thousands or millions of years to decay. The decay rate of a radioactive element is measured in half-lives. After one half-life, half of the radioctivity is gone. Take an element with a half-life of ten years. After ten years, there is half of the radioactivity present. After 20 years, one quarter, after 30 years, one eighth, and so forth. Eventually the level will fall to the point it poses no danger. Plutonium-239 has a half-life of 24,000 years. Uranium-235, used in nuclear reactors, has a half-life of 713,000,000 years.
Uranium-239 does NOT decay by alpha decay, it decays only by beta and gammadecay.
Neptunium-239 must undergo beta decay to generate plutonium-239.
U-238 undergoes neutron capture to form U-239 which decays to Np-239 and further to Pu-239. Pu-239 then undergoes beta decay to form Pu-241. The balanced nuclear equation is: U-238 + n --> U-239 --> Np-239 --> Pu-239 --> Pu-241.
plutonium-239
Yes, plutonium-239 emits alpha particles by decay.
Uranium-238 is converted to plutonium-239 through a process called nuclear transmutation. This typically involves bombarding uranium-238 with neutrons in a controlled environment, such as a nuclear reactor. The uranium-238 absorbs a neutron and undergoes a series of nuclear reactions, eventually transforming into plutonium-239.
Plutonium 239 is obtained in all reactors using uranium as nuclear fuel.
The daughter isotope of Pu-239 is U-235.
Plutonium for nuclear weapons is obtained in special nuclear reactors for plutonium-239.
The most common plutonium isotope is plutonium 239.
Typically, a nuclear bomb would use plutonium-239 as the primary isotope for fission. Plutonium-239 is preferred due to its high fissionability and ease of obtaining through processing in nuclear reactors. Small amounts of other plutonium isotopes, such as plutonium-240, may also be present due to the manufacturing process, but the majority would be plutonium-239.
Plutonium is obtained in nuclear reactors:U-238(n,gamma).................U-239(beta)...................Np-239(beta).................Pu-239