Describe the function of a salt bridge, What would happen if the half-cell compartments of a galvanic cell were not connected?
My electrochemical knowledge is a wee bit rusty, but I believe the salt bridge helps balance the charges and not mass.

What charge you ask? So, let imagine you start up your galvanic cell (below). Electrons from the Zn move to Cu electrode. You start to build up a negative charge on the Cu which would resist/repel further addition of electrons after a period of time, hence production of electricity ceases.

By having a salt bridge, the electrolyte ions can move from one side to the other to mitigate this issue.