The number of elements which should be theoreitcally present in `8^(th)` period of the modern long fromof periodic table, is

Options

A. 32
B. 40
C. 50
D. 48

Answer

To determine the number of elements that should theoretically be present in the 8th period of the modern long form of the periodic table, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Electron Shells and Orbitals**:
- The 8th period corresponds to the principal quantum number \( n = 8 \).
- The orbitals that will be filled in this period are \( 8s, 5g, 6f, 7d, \) and \( 8p \).

2. **Determine the Number of Elements in Each Subshell**:
- **8s**: This subshell can hold a maximum of 2 electrons.
- **5g**: The g subshell can hold a maximum of 18 electrons (since it has 9 orbitals).
- **6f**: The f subshell can hold a maximum of 14 electrons.
- **7d**: The d subshell can hold a maximum of 10 electrons.
- **8p**: The p subshell can hold a maximum of 6 electrons.

3. **Calculate the Total Number of Elements**:
- Adding the maximum number of electrons from each subshell:
\[ \text{Total} = 2 \, (8s) + 18 \, (5g) + 14 \, (6f) + 10 \, (7d) + 6 \, (8p) \]
- Performing the addition:
\[ \text{Total} = 2 + 18 + 14 + 10 + 6 = 50 \]

4. **Conclusion**:
- Therefore, the total number of elements that should theoretically be present in the 8th period of the periodic table is **50**.

### Final Answer:
The number of elements which should be theoretically present in the 8th period of the modern long form of the periodic table is **50**.

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