In general, electrons are more stable in lower atomic number elements due to two main factors: electron-electron repulsion and electron-nucleus attraction.
Electron-Electron Repulsion: Electrons are negatively charged particles, and they repel each other due to their like charges. In elements with lower atomic numbers, the number of electrons is relatively small, and they are distributed in fewer energy levels or electron shells around the nucleus. With fewer electrons, there is less repulsion between them, resulting in greater stability.
Electron-Nucleus Attraction: Electrons are attracted to the positively charged nucleus of an atom. The attractive force between the electrons and the nucleus is governed by the electrostatic force. In lower atomic number elements, the positive charge of the nucleus is relatively stronger compared to the number of electrons present. This stronger attraction helps to hold the electrons closer to the nucleus, resulting in greater stability.
As the atomic number increases, the number of electrons also increases, leading to an increased electron-electron repulsion. This repulsion makes it more difficult to maintain stable electron configurations. Additionally, the increasing number of electrons can weaken the electron-nucleus attraction, as the positive charge of the nucleus becomes more shielded by the additional electron shells.
These factors contribute to the overall stability of lower atomic number elements. However, it's important to note that electron stability is also influenced by other factors such as the specific electron configuration, energy levels, and orbital arrangements within an atom. The stability of electrons in higher atomic number elements may involve more complex considerations, including interactions between multiple electron shells and subshells.