Assertion (A) Compounds of alkaline earth metal is less ionic than the compounds of alkali metals.
Reason ( R) This is due to small size and increased nuclear charge of alkaline earth metals.

Options

A. Both Assertion and reason are correct and Reason is the correct explanation of the Assertion
B. Both assertion and Reason are correct but Reason is not the correct explanation of Assertion
C. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are Incorrect

Answer

To solve the assertion and reason question regarding the ionic character of compounds formed by alkaline earth metals and alkali metals, we can follow these steps:

### Step 1: Understand the Assertion
The assertion states that compounds of alkaline earth metals are less ionic than those of alkali metals.

### Step 2: Analyze the Reason
The reason provided states that this is due to the small size and increased nuclear charge of alkaline earth metals.

### Step 3: Compare Ionic Character
To determine the ionic character, we need to consider the factors that influence it:
- **Cation Size**: Larger cations tend to form more ionic compounds. Alkaline earth metals (Group 2) have smaller cations compared to alkali metals (Group 1).
- **Anion Size**: Larger anions also favor ionic character. The anions involved in compounds with alkaline earth metals are typically the same as those with alkali metals.
- **Charge**: Higher charge on the cation increases covalent character. Alkaline earth metals have a +2 charge, while alkali metals have a +1 charge.

### Step 4: Conclusion on Assertion
Since alkaline earth metals have smaller cations and a higher charge, they exhibit a greater covalent character, making their compounds less ionic compared to those of alkali metals. Thus, the assertion is correct.

### Step 5: Conclusion on Reason
The reason states that the small size and increased nuclear charge of alkaline earth metals contribute to their lower ionic character. This is also correct because a smaller cation size and higher charge lead to increased covalent character.

### Step 6: Final Evaluation
Both the assertion and reason are correct, and the reason correctly explains the assertion. Therefore, the answer is that both the assertion and reason are correct, and the reason is a correct explanation of the assertion.

### Final Answer:
Both assertion and reason are correct, and the reason is the correct explanation of the assertion.

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