Why does distilled water not conduct electricity, whereas rain water does?

Explanation

Distilled water does not conduct electricity because it does not contain any ionic compunds (like acids, bases or salts) dissolved in it. When rain water falls to the earth through the atmosphere, it dissolves an acidic gasl carbon dioxide from the air and forms some carbonic acid `(H_(2)CO_(3))`. Carbonic acid `(H_(2)CO_(3))` provides some hydrogen ions [`H^(+)` (aq) ions) and carbonate ions [`CO_(3)^(2-)` (aq) ions ] to rain water. Due to the presence of these ions rain water conducts electricity.