Why is the uranium nucleus unstable?

²³⁵U A definite ratio of neutron to proton in the nucleus makes the nucleus stable. If the ratio is away from the stability ratio, the nucleus is unstable. In ²³⁵U, 92 protons and 143 neutrons make a ratio 143/92 = 1. read more

There are different isotopes of Uranium. The unstable isotope is because of the proton to neutron ratio in the nucleus of the unstable uranium atom. That’s the simplest answer i can give. read more

Every element from Actinium, number 89, and higher are unstable and sooner or later the repulsion effect causes them to undergo some form of radioactive decay as the nucleus falls from a higher energy state to a lower level. read more

I know the amount of protons in an atom determines what element it is and a certain isotopic ratio of protons to neutrons determines if it is unstable or not, and I always hear how Uranium 235 is the perfect element for nuclear fission because it is unstable and breaks easily. read more