They are synthesized and known as transuranium element. These transuranium elements are element with atomic number higher than 92. Atom are collections of neutrons, proton and electron. Changing of atomic number depends on the proton.
Transuranium element was first prepared in Rome and was made in 1934 by a team of Italian physicists. The team was headed by Enrico Fermi.
All transuranium element are unstable and decay radioactively into other elements. All the transuranium elements found on earth are artificially generated by nuclear reactors or particle accelerators.
Particle accelerators are devices or equipments that make use of electromagnetic energy to accelerate charged particle likes protons, while nuclear reactors are devices that contain radioactive material that are split by free neurons.
These elements are called transuranium or transuranic elements; they are also called man-made or artificial elements because they are created by human manipulation. These elements have existed on earth before but have decayed into more stable elements, and they are found in small quantities. There are different ways these elements are produced which include:
Neutron bombardment involves absorbing a neutron; therefore, they become a heavier isotope of that element. It may undergo beta decay in which the neuron is converted to a proton, and the nucleus increases by one unit.
Fusion involves a combination of two light elements, the combination of these two results to form a heavy element. These particles are brought together with energy to overcome the positively charged nucleus.