In Volta's demonstration, what was placed between the silver and zinc sheets?

In Volta's demonstration, what was placed between the silver and zinc sheets?

• A. Cardboard soaked in saltwater
• B. A thin sheet of mica
• C. Distilled water
• D. Oil

Answer: (A)

The key idea is that an electrolyte between metal electrodes is needed to let ions move and complete the internal circuit, so electric current can flow through the external wires. In Volta’s setup, a piece of cardboard soaked in saltwater sits between the silver (or copper) and zinc sheets. The saltwater provides ions that can carry charge, while the cardboard acts as a porous separator that keeps the metal plates from touching directly and shorting out. This combination allows chemical reactions at the metal surfaces to drive electrons through the external circuit. Why the other options don’t fit: a thin mica sheet is an insulator and would stop ion movement; distilled water has far fewer ions and is a poor conductor compared with saltwater; oil is also an insulating medium and would prevent ion flow.

The key idea is that an electrolyte between metal electrodes is needed to let ions move and complete the internal circuit, so electric current can flow through the external wires.

In Volta’s setup, a piece of cardboard soaked in saltwater sits between the silver (or copper) and zinc sheets. The saltwater provides ions that can carry charge, while the cardboard acts as a porous separator that keeps the metal plates from touching directly and shorting out. This combination allows chemical reactions at the metal surfaces to drive electrons through the external circuit.

Why the other options don’t fit: a thin mica sheet is an insulator and would stop ion movement; distilled water has far fewer ions and is a poor conductor compared with saltwater; oil is also an insulating medium and would prevent ion flow.