Question

why ions conduct electricity?

Answer 1

Conductive when liquid - ions are charged particles, but ionic compounds can only conduct electricity if their ions are free to move. So ionic compounds do not conduct electricity when they are solid, but they do conduct electricity when they are dissolved in water or when they are melted.

Answer 2

Electricity is conducted whenever charge moves from one place to another. This can occur in a couple of ways:

If electrons move from one place to another, electricity is conducted. This happens in the delocalized bonds in metals as well as in static electricity discharge and conductivity in plasmas.If ions move from one place to another, their charges move along with them. As a result, if you have a solution with a dissolved ionic compound (or if you have a melted ionic compound, for that matter), these charges are free to move around if you apply a voltage to them.