🔍 Key Concepts

• Battery chemistry basics: the electrolyte is usually a liquid that allows ions to move between plates • Difference between lead-acid batteries and nickel-cadmium (Ni-Cd) batteries • Common alkaline electrolytes used in rechargeable batteries

💭 Think About

• Ask yourself: which of these substances is commonly associated with lead-acid batteries, and would that likely be used in a nickel-cadmium battery? • Think about whether the electrolyte in a nickel-cadmium battery is acidic or alkaline. • Which option is a strong base often used in alkaline battery systems rather than an acid or a solid compound?

✅ Before You Answer

• Eliminate any answer that is clearly tied to lead-acid battery chemistry. • Check which option is an alkali (base) that would be dissolved in distilled water to form the electrolyte. • Verify that the correct choice is a substance that would be in solution, not the solid active material on the plates.