The number of `pi` bonds in naphthalene is y, number of `sigma` bonds in z and number of carbon atoms is x. calculate the value of `(y+z)/(x)` ?

Answer

To solve the question regarding naphthalene, we need to determine the number of pi bonds (y), sigma bonds (z), and carbon atoms (x) in its structure. Then, we will calculate the value of \((y + z) / x\).

### Step-by-step Solution:

1. **Identify the Structure of Naphthalene**:
- Naphthalene consists of two fused benzene rings. It has a total of 10 carbon atoms.

2. **Count the Number of Carbon Atoms (x)**:
- The structure of naphthalene shows that there are 10 carbon atoms.
- Therefore, \( x = 10 \).

3. **Count the Number of Pi Bonds (y)**:
- Each double bond in the structure contributes one pi bond.
- In naphthalene, there are 5 double bonds.
- Thus, \( y = 5 \).

4. **Count the Number of Sigma Bonds (z)**:
- Each carbon-carbon single bond and each carbon-hydrogen bond contributes one sigma bond.
- In naphthalene, there are:
- 5 carbon-carbon double bonds (which contribute 5 sigma bonds).
- 10 carbon-hydrogen bonds (one for each carbon).
- Additionally, there are 5 carbon-carbon single bonds (from the fused structure).
- Therefore, the total number of sigma bonds is:
- \( z = 5 \text{ (from double bonds)} + 10 \text{ (C-H bonds)} + 5 \text{ (C-C single bonds)} = 19 \).

5. **Calculate \((y + z) / x\)**:
- Now, we can substitute the values we found:
- \( y + z = 5 + 19 = 24 \).
- Thus, \((y + z) / x = 24 / 10 = 2.4\).

### Final Answer:
\[ \frac{(y + z)}{x} = 2.4 \]