Why use u 235

U- is a fissile isotope, meaning that it can split into smaller molecules when a lower-energy neutron is fired at it. U- is a fissionable isotope, meaning that it can undergo nuclear fission, but the neutrons fired at it would need much more energy in order for fission to take place. U- has an even mass, and odd nuclei are more fissile because the extra neutron adds energy - more than what is required to fission the resulting nucleus.

Why is U used more in nuclear reactors than U? Chemistry Nuclear Chemistry Nuclear Chemistry. Inorganic chemistry October 9, August 2, February 18, October 14, October 9, Related Articles. What are some examples of ionic compounds?

October 3, August 1, What is the chemical used in photography? September 26, Nuclear plants in France supply that country with approximately 77 percent of the electricity it requires per year [source: NEI ].

What basic element, found in abundance on Earth, do these nuclear plants require in order to produce these huge amounts of power? The answer is uranium. Nuclear fission occurs when one atom splits into two, creating energy. Spontaneous fission occurs all the time. Uranium undergoes spontaneous fission at a very slow rate, and emits radiation. Uranium U is only found in about 0. The U - nucleus also has 92 protons but has neutrons — three more than U - — and therefore has a mass of units.

The difference in mass between U - and U - allows the isotopes to be separated and makes it possible to increase or "enrich" the percentage of U - Isotopes of uranium.

Uranium 92 U is a naturally occurring radioactive element that has no stable isotope. It has two primordial isotopes, uranium and uranium - , that have long half-lives and are found in appreciable quantity in the Earth's crust. Uranium is the heaviest naturally-occurring element available in large quantities.

Although uranium itself is barely radioactive , the ore which is mined must be regarded as potentially hazardous due to uranium's decay products, especially if it is high-grade ore. The gamma radiation comes principally from isotopes of bismuth and lead in the uranium decay series.

Nuclear energy has no place in a safe, clean, sustainable future. Nuclear energy is both expensive and dangerous, and just because nuclear pollution is invisible doesn't mean it's clean. Renewable energy is better for the environment, the economy, and doesn't come with the risk of a nuclear meltdown. Uranium is a naturally-occurring element in the Earth's crust. To make nuclear fuel from the uranium ore requires first for the uranium to be extracted from the rock in which it is found, then enriched in the uranium - isotope, before being made into pellets that are loaded into assemblies of nuclear fuel rods.

The evidence over six decades shows that nuclear power is a safe means of generating electricity. The risk of accidents in nuclear power plants is low and declining.

The consequences of an accident or terrorist attack are minimal compared with other commonly accepted risks. Uranium - U is an isotope of uranium making up about 0. Unlike the predominant isotope uranium , it is fissile, i.