Which of the following is an example of a galvanic cell? a. a battery that has a negative voltage b. a cell with a nonspontaneous redox reaction c. a battery that produces electricity d. a cell that has energy added to it

A battery that produces electricity

Explanation:

Galvanic cell is a battery which converts chemical energy to electrical energy.

In galvanic cell two half cells work, one is cathodic and other is anodic.

At cathode reduction takes place and at anode oxidation takes place.

Due to this redox reaction some voltage is generated which is known as emf of the cell.

The EMF of the cell calculated from the difference of reduction potential of cathode and anode.

The cell will work if the emf of the cell is positive.

If emf of the cell is positive it means that cell is spontaneous,

Free energy change = ΔG°= -nFE°

thus a positive values of E° corresponds to negative value of ΔG°, and hence a spontaneous reaction.

Where E° is emf of the cell

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.