An atom of an element has electronic configuration 2,8,1. Which of the following statement is correct ?

Options

A. The valency of element is 7
B. The element exists as a triatomic molecule
C. The element is metalloid
D. The element forms basic oxid

Answer

To determine the correct statement regarding the element with the electronic configuration 2, 8, 1, we can follow these steps:

### Step 1: Identify the Element
The electronic configuration 2, 8, 1 indicates that the element has:
- 2 electrons in the first shell
- 8 electrons in the second shell
- 1 electron in the outermost shell (third shell)

This configuration corresponds to sodium (Na), which is in Group 1 of the periodic table.

### Step 2: Determine the Valency
Valency refers to the combining capacity of an element, which is determined by the number of electrons in the outermost shell.
- Since sodium has 1 electron in its outermost shell, it tends to lose that electron to achieve a stable electronic configuration (similar to neon).
- Therefore, the valency of sodium is 1.

### Step 3: Evaluate the Statements
Now, we need to evaluate the given statements:

1. **The valency of the element is 7.**
- This statement is **false** because the valency is 1, not 7.

2. **The element exists as a triatomic molecule.**
- A triatomic molecule consists of three atoms. Sodium, with a valency of 1, typically forms diatomic molecules or ionic compounds, not triatomic ones. This statement is **false**.

3. **The element is a metalloid.**
- Sodium is classified as a metal, not a metalloid. Therefore, this statement is **false**.

4. **The element forms basic oxides.**
- Sodium, being a metal, forms basic oxides (like sodium oxide, Na2O). This statement is **true**.

### Conclusion
The correct statement is that the element forms basic oxides.

### Final Answer
The correct answer is: **The element forms basic oxides.**

---