The correct starting material and product of different disintegration series `"is"//"are"`

Options

A. `Th^(232), Pb^(208)`
B. `Np^(237),Bi^(209)`
C. `U^(235),Pb^(206)`
D. `U^(238),Pb^(206)`

Answer

To solve the question regarding the correct starting material and product of different disintegration series, we will analyze the various radioactive decay series and their end products.

### Step-by-Step Solution:

1. **Identify the Disintegration Series**:
- There are several well-known disintegration series, including the Thorium series, Neptunium series, Uranium series, and Actinium series.

2. **Thorium Series (4n)**:
- **Starting Material**: Thorium-232 (Th-232)
- **End Product**: Lead-208 (Pb-208)
- This series follows the decay of thorium through a series of alpha and beta decays until it stabilizes at lead.

3. **Neptunium Series (4n + 1)**:
- **Starting Material**: Neptunium-237 (Np-237)
- **End Product**: Bismuth-209 (Bi-209)
- This series involves the decay of neptunium through several steps until it reaches bismuth.

4. **Uranium Series (4n + 2)**:
- **Starting Material**: Uranium-238 (U-238)
- **End Product**: Lead-206 (Pb-206)
- The uranium series decays through multiple isotopes until it produces lead.

5. **Actinium Series (4n + 3)**:
- **Starting Material**: Actinium-227 (Ac-227)
- **End Product**: Lead-207 (Pb-207)
- This series also involves a series of decays leading to the stable isotope of lead.

### Summary of Results:
- **Thorium Series**: Th-232 → Pb-208
- **Neptunium Series**: Np-237 → Bi-209
- **Uranium Series**: U-238 → Pb-206
- **Actinium Series**: Ac-227 → Pb-207

### Final Answer:
The correct starting material and product of different disintegration series are:
- **Thorium Series**: Thorium (Th) to Lead (Pb)
- **Neptunium Series**: Neptunium (Np) to Bismuth (Bi)