Which of the following is true for alkali metals ?

Options

A. Strong oxidising agent
B. Weak reducing agent
C. Strong reducing agent
D. Weak oxidising agent

Explanation

To determine which statement is true for alkali metals, let's analyze the properties of these metals step by step.

### Step 1: Identify Alkali Metals
Alkali metals are found in Group 1 of the periodic table. The primary alkali metals include:
- Lithium (Li)
- Sodium (Na)
- Potassium (K)
- Rubidium (Rb)
- Cesium (Cs)

### Step 2: Understand Electropositivity
Alkali metals are characterized by their high electropositivity. This means they have a strong tendency to lose their outermost electron. The electropositivity increases down the group, with cesium being the most electropositive element.

### Step 3: Oxidation and Reduction
When alkali metals lose their outer electron, they undergo oxidation. For example:
- Lithium (Li) → Li⁺ + e⁻
This process indicates that alkali metals are oxidizing themselves, which is a key characteristic of reducing agents.

### Step 4: Classify Reducing Agents
Since alkali metals easily lose their outer electron, they act as strong reducing agents. A reducing agent is a substance that donates electrons in a chemical reaction, causing the reduction of another substance.

### Step 5: Evaluate the Statements
Now, let's evaluate the statements provided in the question:
1. **Strong oxidizing agent?** - Incorrect. Alkali metals do not oxidize other substances; they reduce themselves.
2. **Weak reducing agent?** - Incorrect. Alkali metals are strong reducing agents.
3. **Strong reducing agent?** - Correct. Alkali metals readily lose electrons and thus are strong reducing agents.
4. **Weak oxidizing agent?** - Incorrect. As mentioned, they do not act as oxidizing agents.

### Conclusion
The correct statement regarding alkali metals is that they are **strong reducing agents**.

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