Being radioactive, uranium is not a stable element.
It becomes most stable when its nucleus is filled, not when it is filling it.
Uranium hasn't stable isotopes.
92 protons in uranium nucleus
Thorium, radium, radon, polonium, thallium, etc.
This decay occurs due to the instability of the uranium-238 nucleus, which undergoes alpha decay to achieve a more stable configuration as thorium-234. During alpha decay, a helium nucleus (two protons and two neutrons) is emitted from the uranium-238 nucleus, leading to the transformation into thorium-234.
The nucleus would become unstable because you need a certain amount of neutrons, electrons, and protons for it to be stable.
The nucleus is too large to be stable. There is the theory of grouping of nucleons into alpha particles inside the nucleus and, through oscillations of the nucleus, one of these on one end of the nucleus can be repelled with a great enough force to push it out of the nucleus.
A uranium-235 nucleus must absorb a neutron in order to become unstable and split, a process known as nuclear fission. This absorption of a neutron causes the uranium-235 nucleus to become uranium-236, which then splits into two smaller nuclei, releasing additional neutrons and a large amount of energy.
Radioactive decay of uranium-235 is a process in which the nucleus of a uranium-235 atom transforms into a more stable nucleus by emitting radiation in the form of alpha and beta particles, as well as gamma rays. This decay results in the formation of daughter isotopes and the release of energy.
The resulting nucleus after uranium-238 undergoes 5 successive decay series would be lead-206. Through multiple alpha and beta decays, uranium-238 eventually stabilizes as lead-206, which is a stable isotope.
Uranium is electrically neutral because it has an equal number of positively charged protons and negatively charged electrons. In its stable state, the number of protons in the nucleus is balanced by the number of electrons orbiting around the nucleus, resulting in no overall electrical charge.
Uranium 235 is unstable because it is a radioactive isotope. This means that it is constantly decaying and emitting radiation. The reason it is unstable is because it has too many neutrons in its nucleus. The neutron is a unstable particle, and when there are too many of them in one place, they can cause problems. When uranium 235 decays, it emits alpha particles, which are high-energy particles that can damage DNA and cause cancer.