Anion adalah muatan negatif, yang dihasilkan saat atom/molekul kelebihan elektron. Jika atom X menerima 1 elektron, akan membentuk ion negatif \(\ce{X-}\). Jika atom X menerima 2 elektron, akan membentuk ion negatif \(\ce{X^{2-}}\). Dan seterusnya.
Berikut adalah beberapa contoh anion:
ANION
| Anion | Nama | |
| Golongan IVA | \(\ce{CO3^{2-}}\) | Karbonat |
| \(\ce{SiO3^{2-}}\) | Silikat | |
| Golongan VA | \(\ce{NO2^{-}}\) | Nitrit |
| \(\ce{NO3^{-}}\) | Nitrat | |
| \(\ce{PO3^{2-}}\) | Fosfit | |
| \(\ce{PO4^{2-}}\) | Fosfat | |
| \(\ce{AsO3^{2-}}\) | Arsenit | |
| \(\ce{AsO4^{2-}}\) | Arsenat | |
| \(\ce{SbO3^{2-}}\) | Antimonit | |
| \(\ce{SbO4^{2-}}\) | Antimonat | |
| Golongan VIA | \(\ce{O^{2-}}\) | Oksida |
| \(\ce{S^{2-}}\) | Sulfida | |
| \(\ce{SO3^{2-}}\) | Sulfit | |
| \(\ce{SO4^{2-}}\) | Sulfat | |
| Golongan VIIA | \(\ce{F-}\) | Fluorida |
| \(\ce{Cl-}\) | Klorida | |
| \(\ce{ClO-}\) | Hipoklorit | |
| \(\ce{ClO2-}\) | Klorit | |
| \(\ce{ClO3-}\) | Klorat | |
| \(\ce{ClO4-}\) | Perklorat | |
| \(\ce{Br-}\) | Bromida | |
| \(\ce{BrO4-}\) | Bromat | |
| \(\ce{I-}\) | Iodida | |
| \(\ce{IO4-}\) | Iodat | |
| Anion lainnya | \(\ce{OH-}\) | Hidroksida |
| \(\ce{CN-}\) | Sianida | |
| \(\ce{CH3COO-}\) | Asetat | |
| \(\ce{HCO3-}\) | Bikarbonat | |
| \(\ce{MnO4-}\) | Permanganat | |
| \(\ce{MnO4^{2-}}\) | Manganat | |
| \(\ce{CrO4^{2-}}\) | Kromat | |
| \(\ce{Cr2O7^{2-}}\) | Dikromat |