What are two factors that could slow the transfer of water from the reservoir flask to the receiving flask

The two factors that could slow the transfer of water from the reservoir flask to the receiving flask are pressure on the balloon, amount of water in flask. Water transfer is the movement of water from one place to another using water pipes, reservoir flask and others. Increasing the pressure on the flask and the amount of water will slow down the transfer of water by decreasing its velocity. 

Since valence shells in nonmetal atoms are almost full, the atoms attract electrons and hold them tightly to fill their valence shells.

Explanation:

Electric current can flow freely in a conductor but in an insulator, it cannot flow freely.

The most likely reason that nonmetals are electrical insulators is since valence shells in nonmetal atoms are almost full, the atoms attract electrons and hold them tightly to fill their valence shells.