Verbal agreements are only as good as the paper they are written on. If your friend hasn't paid you for almost a year I wouldn't hold my breath waiting. Just be glad it only cost yo $500 to find out how good a friend they were. It could have cost you thousands of dollars.
Nuclear Materials. Nuclear materials are the key ingredients in nuclear weapons. They include fissile, fussionable and source materials. Fissile materials are those which are composed of atoms that can be split by neutrons in a self-sustaining chain-reaction to release energy, and include plutonium-239 and uranium-235.
In nuclear weapons, the fission energy is released all at once to produce a violent explosion. The most important fissile materials for nuclear energy and nuclear weapons are an isotope of plutonium, plutonium-239, and an isotope of uranium, uranium-235.Uranium-235 occurs in nature.n nuclear weapons, the fission energy is released all at once to produce a violent explosion. The most important fissile materials for nuclear energy and nuclear weapons are an isotope of plutonium, plutonium-239, and an isotope of uranium, uranium-235. Uranium-235 occurs in nature.