Element A has three electrons in the outermost orbit and `B` has six electrons in the outermost orbit The formula of the compound will be .

Options

A. `A_(2)B_(3)`
B. `A_(2)B_(6)`
C. `A_(2)B`
D. `A_(3)B_(2)`

Answer

To determine the formula of the compound formed between elements A and B, we can follow these steps:

### Step 1: Identify the Valency of Each Element
- Element A has 3 electrons in its outermost shell. According to the rules of valency, if the number of valence electrons is between 1 and 4, the valency is equal to the number of valence electrons. Therefore, the valency of element A is **3**.

- Element B has 6 electrons in its outermost shell. If the number of valence electrons is between 5 and 8, the valency is calculated as \(8 - \text{valence electrons}\). Thus, the valency of element B is \(8 - 6 = 2\).

### Step 2: Write the Symbols of the Elements
- The symbols for the elements are:
- Element A: A
- Element B: B

### Step 3: Use the Crisscross Method to Determine the Formula
- Write the valencies of the elements next to their symbols:
- A (valency 3)
- B (valency 2)

- Now, apply the crisscross method:
- The valency of A (3) becomes the subscript for B.
- The valency of B (2) becomes the subscript for A.

- This gives us:
- A becomes \(A_2\) (since we take the valency of B, which is 2)
- B becomes \(B_3\) (since we take the valency of A, which is 3)

### Step 4: Write the Final Formula
- Combining the results from the crisscross method, the formula of the compound is \(A_2B_3\).

### Final Answer
The formula of the compound formed between elements A and B is **A2B3**.

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