The electronic configurations of three elements,
A,B are C are given below. Answer the
questions 14 to 17 on the basis of these
configurations .
`{:(A " "1s^(2) " "2s^(2) " "2p^(6)),(B" "1s^(2) " "2s^(2) " "2p^(6) " " 3s^(2) " "3p^(3)),(C" "1s^(2) " "2s^(2) " "2p^(6) " " 3s^(2) " "3p^(5)):}`
Stable form of a may be represented by the formula :

Options

A. A
B. `A_(2)`
C. `A_(3)`
D. `A_(4)`

Explanation

To determine the stable form of element A based on its electronic configuration, we can follow these steps:

### Step 1: Identify the Electronic Configuration
The electronic configuration of element A is given as:
\[ 1s^2 \, 2s^2 \, 2p^6 \]

### Step 2: Count the Total Number of Electrons
From the configuration, we can count the total number of electrons:
- \(1s^2\) contributes 2 electrons
- \(2s^2\) contributes 2 electrons
- \(2p^6\) contributes 6 electrons

Total electrons = \(2 + 2 + 6 = 10\)

### Step 3: Compare with Noble Gas Configuration
The total of 10 electrons corresponds to the electronic configuration of Neon (Ne), which is a noble gas. Noble gases have complete outer electron shells, making them very stable and unreactive.

### Step 4: Determine the Stability of Element A
Since element A has the same electronic configuration as Neon, it is stable and does not tend to lose or gain electrons. Noble gases exist as monoatomic species because they do not form bonds with other atoms.

### Step 5: Write the Stable Form
Given that element A is stable and exists in a monoatomic form, we can represent its stable form simply as:
\[ A \]

### Final Answer
The stable form of element A may be represented by the formula:
\[ A \]

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