Which expression correctly represents a balanced reduction half-reaction?
a. na+ + e ? na
b. na ? na+ + e
c. cl2 + 2e ? cl
d.2 cl ? cl2 + 2e?

A reduction reaction is one where a chemical species gains electrons or it undergoes a decrease in its oxidation number. The equation that correctly represents this type of reaction is A
Na⁺ + e → Na

Although option C is similar, it does not form chlorine ions with a negative charge, meaning the equation is not balanced.

The chemical bubbles

The teacher is mostly talking about the distillation of a mixture