The reason that no other atoms besides hydrogen form negative ions with more than one proton is primarily due to the distribution of electrons within an atom and the balance between attractive and repulsive forces.
In an atom, negatively charged electrons orbit around a positively charged nucleus, which consists of protons and usually neutrons. The number of protons in the nucleus determines the atomic number and the identity of the element.
When an atom gains or loses electrons, it forms an ion. An ion with a positive charge is called a cation, and an ion with a negative charge is called an anion. Negatively charged anions are formed when an atom gains one or more electrons, resulting in an excess of negative charges relative to the positive charges in the nucleus.
Hydrogen, which has one proton, can form a negative ion called a hydride ion (H-) by gaining an extra electron to achieve a stable electron configuration. However, for elements with more than one proton, it becomes increasingly difficult to form stable negative ions with additional electrons.
This is because as the number of protons increases, the positive charge in the nucleus becomes stronger, exerting a greater pull on the electrons. The increased positive charge creates a stronger electrostatic attraction between the electrons and the nucleus, making it more challenging for the atom to gain additional electrons and form a stable negative ion.
Furthermore, adding electrons to an atom also introduces electron-electron repulsion. The negatively charged electrons repel each other, and as more electrons are added, the repulsion between them becomes more significant. This repulsion further destabilizes the formation of negative ions with multiple electrons.
In summary, the combination of the strong attractive force from the positively charged nucleus and the repulsive forces between electrons makes it energetically unfavorable for atoms with more than one proton to form stable negative ions with additional electrons, unlike hydrogen, which can form a stable hydride ion.