The formula of a compound is `A_(2)B_(5).` The number of electrons in the outermst shells of A and B respectively are:

Options

A. 6 and 3
B. 5 and 6
C. 5 and 2
D. 2 and 3

Answer

To solve the problem, we need to determine the number of electrons in the outermost shells of elements A and B based on the given compound formula \( A_2B_5 \).

### Step-by-Step Solution:

1. **Understand the Compound Formula**:
The formula \( A_2B_5 \) indicates that there are 2 atoms of element A and 5 atoms of element B in the compound.

2. **Identify the Valency**:
The valency of an element is related to the number of electrons in its outermost shell. In this case, we can deduce the valency from the formula:
- The subscript of A (which is 2) suggests that A has a valency of 5.
- The subscript of B (which is 5) suggests that B has a valency of 2.

3. **Determine the Electrons in the Outermost Shell**:
- Since A has a valency of 5, it means that A has 5 electrons in its outermost shell.
- Since B has a valency of 2, it means that B has 2 electrons in its outermost shell.

4. **Final Answer**:
Therefore, the number of electrons in the outermost shells of A and B respectively are:
- A: 5 electrons
- B: 2 electrons

### Conclusion:
The answer is \( 5 \) for A and \( 2 \) for B.