More on basicity
Species having higher negative charge density at a particular atom are more basic. The removal of H+ from a compound EHn increases basicity. For example N3– is a strong base whereas NH3 is weak.
With the exception of Cl–, Br–and I–, anions derived by removal of H+ from EHn are basic. With the exception of F–, they are strong bases.
With the exception of Cl–, Br–and I–, anions derived by removal of H+ from EHn are basic. With the exception of F–, they are strong bases.
increasing acidity  decreasing basicity | |||||||||||||||||||
| The colors code overall acid-base properties (thus NH3 is weakly basic). strong base weak base strong acid weak acid neither acidic or basic | CH4 C4– | NH3 N3– | H2O O2– | HF F– |  | ||||||||||||||
| H2S S2– | HCl Cl– | ||||||||||||||||||
| HBr Br– | |||||||||||||||||||
| HI I– | |||||||||||||||||||