The statement that it is impossible for an atom to have an atomic value (atomic number) greater than A=173 is not accurate.
The atomic number of an atom represents the number of protons in its nucleus. In the periodic table of elements, the atomic numbers range from 1 to 118, corresponding to hydrogen (H) to oganesson (Og), the heaviest known element However, it is important to note that elements with atomic numbers beyond 118 have been predicted theoretically, but they have not yet been synthesized or observed experimentally.
The stability and existence of elements with higher atomic numbers become increasingly challenging as we move towards heavier elements. Elements with extremely high atomic numbers would have a significantly larger number of protons, resulting in stronger electrostatic repulsion between positively charged protons in the nucleus. This repulsion makes it difficult for the nucleus to hold together, which is why these superheavy elements tend to be highly unstable and rapidly decay.
The synthesis and observation of superheavy elements is an ongoing area of research in nuclear physics. Scientists have been able to synthesize and study elements up to atomic number 118 in laboratory settings, using techniques such as nuclear fusion or particle bombardment. However, the synthesis and stability of elements beyond this point present substantial challenges due to their short half-lives and the technical difficulties associated with creating and detecting them.
It is worth noting that scientific knowledge and experimental capabilities continue to evolve, and it is possible that in the future, new techniques and advancements may enable the synthesis and study of elements with even higher atomic numbers.