Agalvanic cell employs the reaction mg2+(aq) + cu(s) → mg(s) + cu2+(aq) and nano3 is the salt used in the salt bridge. during the course of the reaction. a. nano3 leaves the salt bridge and enters the anode compartment. b. na+ leaves the salt bridge and enters the cathode compartment. c. na+ leaves the salt bridge and enters the anode compartment. d. nano3 leaves the salt bridge and enters the cathode compartment.

b. Na+ leaves the salt bridge and enters enters the cathode

Explanation:

A galvanic cell or electrochemical cell depicts an oxidation -reduction half reactions (redox) reaction. it consists of two half cells ; one for the reduction reaction which involves the gain of electrons and the other for the oxidation reaction which involves the loss of electrons.  One half cell contains the anode and oxidation occurs at the anode while the other half cell contains the cathode and reduction occurs at the cathode. The anode is usually connected to the cathode, a salt bridge is added to complete the circuit and allow current to flow. The salt bridge serves as a counter ions, they do not interfere with the electrochemical reaction but provides a passage for the migration of ions thereby preventing the cells from reaching equilibrium too quickly and thus the electrons in the salt are able to move along with any electrons.

In this galvanic cell, Cu at the anode losses two electrons to become Cu2+, and the electrons moves from the anode to the cathode where Mg2+ gain these two electrons to become negatively charged. Positively charged ions in the salt brigde Na+ will move to the cathode to pick negatively charged ions from the cathode solution. this helps to remove the strong negative charge from the cathode and allows the electrons to continue to move to the cathode.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.