The element with `ns^(2)np^(4)` as outer electron configuration is a

Options

A. Alkalimetal
B. Chalcogen
C. Noble gas
D. Halogen

Answer

To determine the element with the outer electron configuration of `ns²np⁴`, we can follow these steps:

### Step 1: Understand the Electron Configuration
The notation `ns²np⁴` indicates that the outermost shell (n) has 2 electrons in the s subshell and 4 electrons in the p subshell. This configuration suggests that the element is in the p-block of the periodic table.

### Step 2: Identify the Period
The outer electron configuration `ns²np⁴` can be broken down as follows:
- The `ns²` part indicates that there are 2 electrons in the s subshell of the outermost shell.
- The `np⁴` part indicates that there are 4 electrons in the p subshell of the same outermost shell.

Since the total number of electrons in the outer shell is 6 (2 from s and 4 from p), we can deduce that the outermost shell corresponds to the 2nd period (for n=2) or higher.

### Step 3: Identify the Group
Elements with the configuration `ns²np⁴` belong to Group 16 of the periodic table. This group is also known as the chalcogens.

### Step 4: List the Elements in Group 16
The elements in Group 16 with their respective outer electron configurations are:
- Oxygen (O): 1s² 2s² 2p⁴
- Sulfur (S): 1s² 2s² 2p⁶ 3s² 3p⁴
- Selenium (Se): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁴
- Tellurium (Te): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁴
- Polonium (Po): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁶ 6s² 6p⁴

### Step 5: Conclusion
The element with the outer electron configuration `ns²np⁴` is therefore found in Group 16. The specific elements that fit this configuration are sulfur (S), selenium (Se), and tellurium (Te) depending on the period.

### Final Answer
The element with the outer electron configuration `ns²np⁴` is a chalcogen, specifically sulfur (S), selenium (Se), or tellurium (Te), depending on the period.

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