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

Distilled water does not conduct electricity because it does not contain any ionic compound (like acids, bases or salts) dissolved in it. On the other hand, rain water conducts electricity. This can be explained as follows: Rain water, while falling to the earth through the atmosphere, dissolves an acidic gas carbon dioxide from the air and forms carbonic acid (H2CO3). Carbonic acid provides hydrogen ions, H+(aq), and carbonate ions, CO2-3 (aq), to rain water. So, due to the presence of carbonic acid (which provides ions to rain water), the rain water conducts electricity.