Elements with outer electron configuration ns2 np6 are:

Options

A. Alkaline earth metals
B. Transition elements
C. Chalcogens
D. Noble gases

Answer

To determine the elements with the outer electron configuration of ns² np⁶, we need to understand what this configuration signifies and identify the elements that possess it.

### Step-by-Step Solution:

1. **Understanding the Electron Configuration**:
- The notation ns² np⁶ indicates that the outermost shell (n) has two electrons in the s subshell and six electrons in the p subshell. This configuration corresponds to a complete octet, which is characteristic of stable electron arrangements.

2. **Identifying Noble Gases**:
- Elements that have a complete octet are typically found among the noble gases in the periodic table. Noble gases are known for their stability and lack of reactivity due to their full valence shell.

3. **Listing the Noble Gases**:
- The noble gases in the periodic table include:
- Helium (He) - 1s²
- Neon (Ne) - 1s² 2s² 2p⁶
- Argon (Ar) - 1s² 2s² 2p⁶ 3s² 3p⁶
- Krypton (Kr) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶
- Xenon (Xe) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁶
- Radon (Rn) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁶ 6s² 6p⁶

4. **Finding the Relevant Elements**:
- From the list above, the elements that have the outer electron configuration of ns² np⁶ are:
- Neon (Ne) - 2s² 2p⁶
- Argon (Ar) - 3s² 3p⁶
- Krypton (Kr) - 4s² 4p⁶
- Xenon (Xe) - 5s² 5p⁶
- Radon (Rn) - 6s² 6p⁶

5. **Conclusion**:
- Therefore, the elements with the outer electron configuration of ns² np⁶ are the noble gases: Neon, Argon, Krypton, Xenon, and Radon.

### Final Answer:
The elements with outer electron configuration ns² np⁶ are the noble gases: Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).