Choose the s-block element from the following:

Options

A. `1s^(2), 2s^(2), 2p^(6), 3s^(2), 3p^(6), 3d^(5), 4s^(1)`
B. `1s^(2), 2s^(2), 2p^(6), 3s^(2), 3p^(6), 3d^(10), 4s^(1)`
C. `1s^(2), 2s^(2), 2p^(6), 3s^(2), 3p^(6), 4s^(1)`
D. all of the above

Answer

To determine the s-block element from the given options, we need to understand the characteristics of s-block elements in the periodic table. Here’s a step-by-step solution:

### Step 1: Understand the s-block elements
- The s-block elements are found in Group 1 and Group 2 of the periodic table.
- These elements have their outermost electrons in the s orbital, which can be represented by the general electronic configurations of ns¹ or ns², where n is the principal quantum number.

### Step 2: Analyze the given electronic configurations
- We need to look at the electronic configurations provided in the options (though the specific options are not listed here, we can infer from the transcript).
- The configurations mentioned in the transcript include:
- 3D⁵ 4S¹ (which corresponds to chromium)
- Other configurations that may correspond to d-block elements.

### Step 3: Identify the correct s-block configuration
- From the transcript, it is indicated that the configuration 3D⁵ 4S¹ corresponds to chromium, which is a d-block element.
- For an element to be classified as s-block, its outermost electrons must be in the s orbital (ns¹ or ns²).

### Step 4: Conclusion
- Based on the analysis, the correct option for an s-block element would be one that has an electronic configuration ending in ns¹ or ns², and not one that has electrons in the d orbital as in the case of chromium (3D⁵ 4S¹).
- Therefore, the answer is the option that fits the s-block criteria, which is not explicitly mentioned in the transcript but is implied to be option C.

### Final Answer
The required s-block element is option C.

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