🔍 Key Concepts

• Construction of Edison-type alkaline storage batteries • Difference between positive and negative plates in Edison cells • Common active materials used in nickel-iron (NiFe) batteries

💭 Think About

• Think about which metal and compound is typically associated with Edison nickel-iron batteries. • Ask yourself: in an Edison cell, which plate (positive or negative) is linked with nickel and which with iron? • Consider which of the listed substances are realistic active materials for early-20th-century storage batteries.

✅ Before You Answer

• Verify which substance is used on the positive plate specifically, not just in the cell in general. • Eliminate any option that is not a typical active material in nickel-iron alkaline batteries. • Check basic battery chemistry: which option pairs logically with iron as the other electrode material?