Nucleus of an element contains 9 protons Its valency would be :

Options

A. 1
B. 2
C. 3
D. 5

Answer

To determine the valency of an element with a nucleus containing 9 protons, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Element**:
- The number of protons in the nucleus of an element is equal to its atomic number. Here, the element has 9 protons.
- Therefore, the atomic number of the element is 9.

2. **Determine the Element Name**:
- The element with atomic number 9 is Fluorine (F).

3. **Electronic Configuration**:
- The electronic configuration of Fluorine can be written as follows:
- The first shell (1s) can hold up to 2 electrons, and the second shell (2s and 2p) can hold up to 8 electrons.
- For Fluorine (9 electrons), the configuration is:
- 1s² 2s² 2p⁵
- This means:
- 2 electrons in the 1s orbital
- 2 electrons in the 2s orbital
- 5 electrons in the 2p orbital

4. **Determine the Valency**:
- The outermost shell (the second shell in this case) has 7 electrons (2 in 2s and 5 in 2p).
- To achieve a stable octet (8 electrons), Fluorine needs to gain 1 more electron.
- Therefore, the valency of Fluorine is 1, as it can gain one electron to complete its outer shell.

5. **Conclusion**:
- The valency of the element with 9 protons (Fluorine) is 1.