Uranium-235 is essential in the nuclear industry, as it decays through alpha radiation and is the only naturally-occurring uranium isotope that can sustain a chain reaction, even an induced one. Australia, Kazakhstan, Canada and Russia own the largest known uranium resources.
One of the three isotopes of natural uranium, the others being Uranium-238 and Uranium-234, Uranium-235 has 143 neutrons. Its decay generates alpha, beta and gamma radiation. It is the only naturally-occurring fissile isotope, and is 18.7 times denser than water and has a half-life of 703.8 million years.
The radioactivity of uranium-235 makes it extremely harmful for humans when ingested or inhaled, causing a number of serious conditions
Contamination can occur through inhalation during mining or milling, or indirectly through contaminated groundwater.
Uranium-234 is one of the three isotopes of uranium and the last isotope that still occurs in nature. Uranium-234 is used in the making of nuclear weapons and nuclear fuels.
Isotopes of uranium-234 can be found on earth's crust (as an indirect result of the Uranium-238 decay). This type of isotope has a half-life of 2.46x105 years.
Uranium can be used in metal or uranium dioxide form to make nuclear weapons, tank armor plating, fuel for nuclear plants and submarines.
Uranium emits a series of gamma ray particles that pose health risks only if they are inhaled or ingested. When they get inside the body, this particles cause lung and bone cancer. High concentrations of uranium can cause serious damage to all internal organs.