The reason that no other atoms besides hydrogen form negative ions with more than one proton is primarily due to their electron configuration and the relative strengths of the electrostatic forces involved.
Negative ions are formed when an atom gains one or more electrons, resulting in an excess of negatively charged particles (electrons) compared to the positively charged particles (protons) in the nucleus. For an atom to form a stable negative ion, it typically requires a relatively low amount of energy to add an electron(s) and achieve a stable electron configuration.
Hydrogen, with its single proton, can easily form a negative ion (H-) by gaining one electron to complete its electron shell. The added electron fills the 1s orbital, resulting in a stable configuration similar to helium (He).
However, atoms with more than one proton have additional positively charged protons in their nuclei. These extra protons create stronger positive charges in the nucleus, exerting a greater electrostatic attraction on electrons compared to hydrogen.
As the number of protons increases, the electrostatic attraction between the positively charged nucleus and the negatively charged electrons becomes stronger. This increased attraction makes it more difficult for these atoms to gain additional electrons and form stable negative ions. The added electrons would experience a stronger pull from the nucleus, requiring more energy to overcome the increased electrostatic forces.
Instead of gaining additional electrons to form negative ions, atoms with more than one proton tend to form positive ions (cations) by losing one or more electrons. By losing electrons, these atoms achieve a stable electron configuration by reaching a noble gas configuration, where the outermost energy level is completely filled.
In summary, while hydrogen can form a negative ion by gaining one electron, atoms with more than one proton have stronger electrostatic forces that make it energetically unfavorable for them to form negative ions. These atoms typically achieve stability by losing electrons and forming positive ions.