Which of these metals is the least reactive?

Options

A. Copper
B. Gold
C. Lead
D. Iron

Answer

To determine which of the given metals is the least reactive, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Reactivity Series**: The reactivity series is a list of metals arranged in order of their reactivity from highest to lowest. Knowing this series helps us identify which metals are more reactive and which are less reactive.

2. **List the Metals in the Reactivity Series**: The reactivity series generally includes the following metals in order:
- Potassium (K)
- Sodium (Na)
- Calcium (Ca)
- Magnesium (Mg)
- Aluminum (Al)
- Zinc (Zn)
- Iron (Fe)
- Lead (Pb)
- Hydrogen (H)
- Copper (Cu)
- Silver (Ag)
- Gold (Au)
- Platinum (Pt)

3. **Identify the Given Metals**: From the question, we have the following metals to consider:
- Copper (Cu)
- Gold (Au)
- Lead (Pb)
- Iron (Fe)

4. **Locate Each Metal in the Reactivity Series**:
- Copper is located above silver and below iron in the reactivity series.
- Gold is located below silver and is one of the least reactive metals.
- Lead is located above hydrogen but below iron.
- Iron is located above lead in the series.

5. **Determine the Least Reactive Metal**: By comparing the positions of the given metals in the reactivity series, we can see that gold (Au) is the least reactive metal among the options provided.

6. **Conclude the Answer**: Therefore, the answer to the question "Which of these metals is the least reactive?" is **Gold (Au)**.

### Final Answer:
The least reactive metal among the options is **Gold (Au)**.

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