How many of the following elements show `+2` as their most stable oxidation state ?
`Sc, Sn, Zn, Be, Pb, Co, Ag, Ti, Fe`

Explanation

To determine how many of the given elements show +2 as their most stable oxidation state, we will analyze each element one by one.

### Step-by-Step Solution:

1. **Scandium (Sc)**:
- Scandium typically exhibits a +3 oxidation state as its most stable state.
- **Conclusion**: Does not show +2 as the most stable oxidation state.

2. **Tin (Sn)**:
- Tin can exhibit oxidation states of +2 and +4, but +2 is often more stable in certain compounds.
- **Conclusion**: Shows +2 as a stable oxidation state.

3. **Zinc (Zn)**:
- Zinc predominantly shows a +2 oxidation state, which is its most stable state.
- **Conclusion**: Shows +2 as the most stable oxidation state.

4. **Beryllium (Be)**:
- Beryllium typically shows a +2 oxidation state as its most stable oxidation state.
- **Conclusion**: Shows +2 as the most stable oxidation state.

5. **Lead (Pb)**:
- Lead can exhibit +2 and +4 oxidation states, but +2 is often more stable in many compounds.
- **Conclusion**: Shows +2 as a stable oxidation state.

6. **Cobalt (Co)**:
- Cobalt can exhibit +2 and +3 oxidation states, with +2 being quite stable.
- **Conclusion**: Shows +2 as the most stable oxidation state.

7. **Silver (Ag)**:
- Silver primarily shows a +1 oxidation state, which is its most stable state.
- **Conclusion**: Does not show +2 as the most stable oxidation state.

8. **Titanium (Ti)**:
- Titanium typically shows +4 as its most stable oxidation state.
- **Conclusion**: Does not show +2 as the most stable oxidation state.

9. **Iron (Fe)**:
- Iron can exhibit +2 and +3 oxidation states, with +2 being stable in many cases.
- **Conclusion**: Shows +2 as a stable oxidation state.

### Summary of Findings:
- Elements that show +2 as their most stable oxidation state: Sn, Zn, Be, Pb, Co, Fe.
- Total count: 6 elements.

### Final Answer:
**6 elements show +2 as their most stable oxidation state.**

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