Outer configuration of `X` is `3d^5,4s^1` . It belongs to group number -

Explanation

To determine the group number of the element `X` with the outer electronic configuration `3d^5 4s^1`, we can follow these steps:

### Step 1: Identify the outer electronic configuration
The outer electronic configuration given is `3d^5 4s^1`. This means that there are 5 electrons in the `3d` subshell and 1 electron in the `4s` subshell.

### Step 2: Determine the total number of electrons in the outer shell
To find the group number, we need to sum the electrons in the outermost `s` and `d` subshells:
- Electrons in `4s`: 1
- Electrons in `3d`: 5

Total = 1 (from `4s`) + 5 (from `3d`) = 6

### Step 3: Identify the group number
In the periodic table, the group number for elements in the d-block can be determined by the total number of electrons in the outermost `s` and `d` subshells. Since we calculated a total of 6, we can conclude that the element belongs to Group 6.

### Conclusion
The element `X` with the outer electronic configuration `3d^5 4s^1` belongs to Group 6.

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