uranium
Element number 92 is Uranium and there are two main isotopes - U235 and U238. In U235 there are 92 protons so there are 235 - 92 = 143 neutrons. In U238 there are thus 146 neutrons
The same name with a different atomic mass number. As an example U235 and U238 are two isotopes of Uranium
Yes, U233, U235, and U238 are all used as nuclear fuels.
Isotopes. eg U235 and U238. Both Uranium, atomic number 92, bur different isotopes.
Neutrons in the nucleus of the element's atoms. It is the number of protons in the nucleus that determines what the element is. It is the total of neutrons and protons in the nucleus that gives the isotope number. Uranium generally comes in two isotopes, U235 and U238. All uranium is radioactive -- that is, it will decay into other elements over time. U238 is much more common and is very long lived radioactively and is not explosive and cannot be made into atomic bombs. U235 is much rarer, but is highly radioactive and can be made into atomic bombs. The two isotopes are mixed together at the atomic level. This is what Iran is trying to do now in it's efforts to concentrate enough U235 to make a bomb -- the process is called "enrichment."
Isotopes of elements are atoms with the same number of protons but different numbers of neutrons. This causes isotopes of the same element to have different atomic masses. Isotopes can be stable or unstable, with unstable isotopes undergoing radioactive decay.
It depends on the type of reactor you're using. For light-water reactors, the most common type of reactor, the ratio of U235/U238 is usually around 3.5%.
This means that the nuclear material is of a high enough concentration to fissile (allow for a fission chain reaction). This is because Uranium comes naturally as 99.3% U238, which cannot sustain fission, and .7% U235, which is what they want for the fuel. So they have to find away to pull away the U238 and leave the U235. As they concentrate the U235, it becomes concentrated enough so that it can sustain fission (too much U238 bogs down the reaction and will eventually end the fission). When it reaches this point of concentration, it is concidered reactor grade. Different elements have different needed concentrations to reach this level.
where does the element silicon come from? where does the element silicon come from?
U238 is a stable isotope of uranium - it doesn't undergo decay except at a very very slow rate unless hit with Neutrons - then it will decay to Neptunium
Depends on the isotope. Most uranium found naturally is U238 and hence 238 g would be 1 mole. U235 used for fission and bombs would be 235g.
It comes from the fission of certain nuclei, mostly U235 and Pu239. Every fission of a nucleus of an atom of these materials releases a certain amount of energy as heat.