In Mendeleev table, the triad of VIII group is :

Explanation

To solve the question regarding the triads of the VIII group in Mendeleev's periodic table, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding Triads**:
- Triads are groups of three elements where the atomic mass of the middle element is approximately the average of the atomic masses of the other two elements.

2. **Identifying Group VIII**:
- In Mendeleev's periodic table, Group VIII consists of transition metals. We need to identify the triads within this group.

3. **Listing the Triads**:
- In Group VIII, there are three notable triads:
- **First Triad**: Iron (Fe), Cobalt (Co), Nickel (Ni)
- **Second Triad**: Ruthenium (Ru), Rhodium (Rh), Palladium (Pd)
- **Third Triad**: Osmium (Os), Iridium (Ir), Platinum (Pt)

4. **Conclusion**:
- Therefore, the triads of Group VIII in Mendeleev's table are:
- Iron, Cobalt, Nickel
- Ruthenium, Rhodium, Palladium
- Osmium, Iridium, Platinum

### Final Answer:
The triads of Group VIII in Mendeleev's table are:
1. Iron (Fe), Cobalt (Co), Nickel (Ni)
2. Ruthenium (Ru), Rhodium (Rh), Palladium (Pd)
3. Osmium (Os), Iridium (Ir), Platinum (Pt)

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