Which one of the following metals do not react with cold as well as hot water ?

Options

A. Na
B. Ca
C. Mg
D. Fe

Explanation

To determine which metal does not react with cold or hot water, we can analyze the reactivity of different metals with water. Here’s a step-by-step solution:

### Step 1: Identify Metals that React with Cold Water
Some metals react with cold water. These include:
- Sodium (Na)
- Potassium (K)
- Calcium (Ca)

### Step 2: Identify Metals that React with Hot Water
Certain metals react with hot water. An example is:
- Magnesium (Mg)

### Step 3: Identify Metals that React with Steam
Some metals do not react with cold or hot water but do react with steam. These include:
- Zinc (Zn)
- Iron (Fe)

### Step 4: Identify Metals that Do Not React with Water
There are metals that do not react with water in any form (cold, hot, or steam). These include:
- Copper (Cu)
- Silver (Ag)
- Gold (Au)

### Step 5: Conclusion
Among the metals listed, Iron (Fe) does not react with cold or hot water; it only reacts with steam. Therefore, the correct answer to the question "Which one of the following metals do not react with cold as well as hot water?" is **Iron (Fe)**.

### Final Answer
**Iron (Fe)** is the metal that does not react with cold or hot water.

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