You have got #"ammonia"#, #NH_3#, a room temperature gas, with a strong penetrating odour. Because hydrogen is bound to the more electronegative nitrogen atom, bond polarity is generated to give #""^(-delta)NH_3""^(delta+)#, with the result that ammonia is a water-like solvent, that has very high solubility in aqueous solution....
In aqueous solution, ammonia behaves as a WEAK Bronsted base....
#NH_3(aq) + H_2O(l) rightleftharpoons NH_4^+ +HO^(-)#
While the equilibrium lies to the left, #"ammonium salts"#, i.e. #NH_4^(+)X^-# can be readily isolated by addition of stoichiometric #HX#.
Now the nitrogen centre may be substituted with hydrocarbyl groups...to give #RNH_2#, #"primary amines"#, #R_2NH#, #"secondary amines"#, #R_3N#, #"tertiary amines"#, and #R_4N^+#, #"quaternary ammonium salts....."#
