What is the key characteristic of an oxidation–reduction reaction?
A.
Electricity is gained.
B.
Electricity is lost.
C.
Electrons are exchanged.
D.
Electrons are gained.
E.
Electrons are lost.

C. Electrons are exchanged

Explanation:

Oxidation-Reduction reaction (Redox) is a type of chemical reaction in which there is a transfer of electrons between the reacting substance.

In this type of reaction, one of the reacting substance, called the Reducing  Agent, undergoes Oxidation (loss of electrons), while the other reacting substance, called the Oxidising Agent ,undergoes Reduction (gains electron).

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.