When an element's nucleus changes to that of a new element, the process is called:

Question

mutation. radiation. ionic radioactivity. radioactive decay.

Answer 1

A radioactive element undergoes RADIOACTIVE DECAY, either through alpha particle emission, beta particle emission, or electron capture.  In the process of any of these, the nucleus changes from one element to another.

It is also possible to change an element by transmutation, in which a smaller nucleus is forced into a larger nucleus to make an even bigger nucleus.

Answer 2

A radioactive or unstable element loses parts of its nucleus through nuclear decay or radioactive decay. Unstable elements can also be changed through nuclear fission, which is where the nucleus becomes unstable after gaining extra neutrons (U235 becomes U236, which breaks into isotopes of barium and krypton). Another possibility is once again with nuclear elements. Thermonuclear Fusion. This happens when atoms of elements, under the heat of nuclear fission are combined through pressure. Take Tritium and Deuterium for example. When they are combined at extreme heat, the tritium (2 neutrons, 1 proton, 1 electron) and deuterium (1 proton, 1 neutron, 1 electron) combine to produce Helium 3, 1 neutron, and a lot of energy. Take note that an element only becomes a different element if the number of electrons in the orbitals change. Extra subatomic particles in the nucleus only make an isotope of the original element. The last way is atomic transmutation. That is when multiple atoms and subatomic particles are fused together using extreme amounts of energy to form another element. Hope this helps