Arrange the following metals in the decreasing order of reactivity:

Sodium > iron > silver > gold

The correct answer is option 4. Sodium > iron > silver > gold.

The correct order of the metals in decreasing order of reactivity is Sodium > iron > silver > gold. Metals are arranged in order of reactivity based on their tendency to lose electrons in chemical reactions. Sodium is highly reactive and readily loses its outer electron to form a sodium ion, followed by iron, which is moderately reactive. Silver is less reactive than iron, and gold is the least reactive among the listed metals. Therefore, sodium is the most reactive, followed by iron, silver, and gold.