Write the chemical name of vitamin `B_(12)`.

Explanation

To answer the question about the chemical name of vitamin B12, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Vitamin**: We are asked for the chemical name of vitamin B12.

2. **Chemical Name**: The chemical name of vitamin B12 is **Cyanocobalamin**. This name indicates that the vitamin contains a cyanide group (cyano) and is a cobalamin, which refers to its cobalt content.

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