What are the factors which stabilize negative charge in organic chemistry?

One factor is that species with lower negative charges are generally more stable than those with higher negative charges. Another factor is that as polarizability increases down the periodic table, the stability of negative charge also increases. Larger atoms, like iodine, have greater polarizability compared to smaller atoms like fluorine, making negative charges more stable. A third factor is resonance stabilization. Negative charges adjacent to pi (π) bonds can be stabilized through resonance, where the charge is delocalized over multiple atoms. Negative charges adjacent to electron-withdrawing groups are more stable than those without. For instance, a negative charge next to a group like CCl3(-) is more stable than if it were adjacent to H3C(-). Another factor is increasing s-character in the hybridization of an atom, such as going from sp3 to sp2 to sp, increases the stability of negative charges. Lastly, as electronegativity increases across the periodic table, the stability of negative charge also increases.