If period number and grou number of any representative element(s) are same then which of the following statement is incorrect regarding such type element(s) in their ground state? (period number and group number are according to modern form of periodic table)

Options

A. The possible value of principan quantum number is 2
B. The possible value of azimuthal quantum number is zero
C. The possible value of magnetic quantum number is 1
D. the species could be paramagnetic

Explanation

To solve the question, we need to analyze the statements regarding representative elements whose period number and group number are the same. The only representative elements that fit this criterion are hydrogen and beryllium.

### Step-by-Step Solution:

1. **Identify the Elements**:
- The elements with the same period number and group number are hydrogen (H) and beryllium (Be).
- Hydrogen is in period 1, group 1, and beryllium is in period 2, group 2.

2. **Examine the Ground State Electronic Configurations**:
- Hydrogen has the electronic configuration of 1s¹.
- Beryllium has the electronic configuration of 1s² 2s².

3. **Evaluate Each Statement**:
- **Statement 1**: "The possible value of principal quantum number is 2."
- For beryllium (2s²), the principal quantum number (n) is indeed 2. However, for hydrogen (1s¹), the principal quantum number is 1. Thus, this statement is correct for beryllium but not for hydrogen.

- **Statement 2**: "The possible value of azimuthal quantum number is 0."
- The azimuthal quantum number (l) for the s subshell is 0. Both hydrogen and beryllium have their outermost electrons in the s subshell, making this statement correct.

- **Statement 3**: "The possible value of magnetic quantum number is 1."
- The magnetic quantum number (m) can take values from -l to +l. Since l = 0 for s subshells, the only possible value for m is 0. Therefore, this statement is incorrect.

- **Statement 4**: "The species could be paramagnetic."
- Hydrogen has one unpaired electron, making it paramagnetic. Beryllium, with paired electrons, is diamagnetic. Thus, this statement is correct for hydrogen.

4. **Conclusion**:
- The incorrect statement regarding the representative elements (hydrogen and beryllium) is **Statement 3**: "The possible value of magnetic quantum number is 1."

### Final Answer:
The incorrect statement is: **The possible value of magnetic quantum number is 1.**

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