Choose the correct options from the following: 

Options

A. Cr and S have the same number of valence shell electrons.
B. Cr and S have different number of unpaired electrons in their ground state.
C. Cr and S are the elements of the same period.
D. In the long form of the periodic table, the Group number of Cr and S is 6 and 16, respectively.

Answer

To solve the question, we need to evaluate the given statements about Chromium (Cr) and Sulphur (S) based on their electronic configurations and properties. Let's analyze each statement step by step.

### Step 1: Determine the valence shell electrons of Chromium and Sulphur.
- **Chromium (Cr)** has the electronic configuration:
- \( [Ar] 3d^5 4s^1 \)
- Valence shell electrons = 5 (from 3d) + 1 (from 4s) = 6 electrons.

- **Sulphur (S)** has the electronic configuration:
- \( [Ne] 3s^2 3p^4 \)
- Valence shell electrons = 2 (from 3s) + 4 (from 3p) = 6 electrons.

**Conclusion**: Both Chromium and Sulphur have the same number of valence shell electrons (6).

### Step 2: Determine the number of unpaired electrons in Chromium and Sulphur.
- For **Chromium (Cr)**:
- The 3d subshell has 5 electrons, which can be represented as:
- \( \uparrow \uparrow \uparrow \uparrow \uparrow \) (5 unpaired electrons in 3d)
- The 4s subshell has 1 electron:
- \( \uparrow \) (1 unpaired electron in 4s)
- Total unpaired electrons in Chromium = 5 (from 3d) + 1 (from 4s) = 6 unpaired electrons.

- For **Sulphur (S)**:
- The 3s subshell has 2 electrons:
- \( \uparrow\downarrow \) (0 unpaired electrons in 3s)
- The 3p subshell has 4 electrons, which can be represented as:
- \( \uparrow \uparrow \uparrow \uparrow \) (2 unpaired electrons in 3p)
- Total unpaired electrons in Sulphur = 0 (from 3s) + 2 (from 3p) = 2 unpaired electrons.

**Conclusion**: Chromium has 6 unpaired electrons, while Sulphur has 2 unpaired electrons. Therefore, they have different numbers of unpaired electrons.

### Step 3: Determine if Chromium and Sulphur are in the same period.
- **Chromium (Cr)** is in the 4th period of the periodic table.
- **Sulphur (S)** is in the 3rd period of the periodic table.

**Conclusion**: Chromium and Sulphur are not in the same period.

### Step 4: Determine the group numbers of Chromium and Sulphur.
- **Chromium (Cr)** is in group 6 of the periodic table (D-block element).
- **Sulphur (S)** is in group 16 of the periodic table (Chalcogen group).

**Conclusion**: The group numbers of Chromium and Sulphur are 6 and 16, respectively.

### Final Evaluation of Statements:
1. Chromium and Sulphur have the same number of valence shell electrons. **(Correct)**
2. Chromium and Sulphur have different numbers of unpaired electrons in their ground state. **(Correct)**
3. Chromium and Sulphur are the elements of the same period. **(Incorrect)**
4. In the long form of the periodic table, the group number of Chromium is 6 and of Sulphur is 16. **(Correct)**

### Correct Options:
The correct options are 1, 2, and 4.

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