CH₃⁻
F⁻
OH⁻
NH₂⁻
A nucleophile is a chemical species that donates an electron pair to an electrophile to form a chemical bond in relation to a reaction. Electronegativity – “greed for electrons” – is the opposite of nucleophilicity – “giving away electrons”. So, less the electronegativity, more the nucleophilicity of the ion. CH₃⁻ has the highest nucleophilicity. Nucleophilicity decreases as CH₃⁻ > NH₂⁻ > OH⁻ > F⁻