Which of the following have transition metal?

Options

A. Haemoglobin
B. Vitamin `B_(12)`
C. Cis-platin
D. Chlorophyll

Explanation

To determine which of the given options contain transition metals, we first need to understand what transition metals are. Transition metals are defined as the elements that belong to the d-block of the periodic table. These elements typically have partially filled d-subshells and are found between the s-block and p-block elements.

### Step-by-Step Solution:

1. **Identify the Elements in Each Option**:
- **Haemoglobin**: Contains iron (Fe).
- **Vitamin B12**: Contains cobalt (Co).
- **Cisplatin**: Contains platinum (Pt).
- **Chlorophyll**: Contains magnesium (Mg).

2. **Determine the Classification of Each Element**:
- **Iron (Fe)**: This is a transition metal as it is located in the d-block.
- **Cobalt (Co)**: This is also a transition metal as it is in the d-block.
- **Platinum (Pt)**: This is a transition metal as it is found in the d-block.
- **Magnesium (Mg)**: This is not a transition metal; it belongs to the s-block (Group 2).

3. **Conclusion**:
- The options that contain transition metals are:
- Haemoglobin (contains Fe)
- Vitamin B12 (contains Co)
- Cisplatin (contains Pt)
- Chlorophyll does not contain a transition metal as it contains magnesium.

### Final Answer:
The correct options that contain transition metals are Haemoglobin, Vitamin B12, and Cisplatin (options A, B, and C).

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